The Specs
The camera has a 9 megapixel sensor, with optical image stabilization. 9 megapixels is a lot and pretty much more than anybody really needs, given that most computer LCDs can't even show a full 2 megapixel image. There' s no reason to hold out for a larger MP camera.
The camera weighs 245 grams without batteries, and with 2AAs, the weight comes up to about 300g. It does not have an optical viewfinder, but makes up for it with a large 3 inch LCD with 230k pixels that is bright, clear, and pretty color accurate. The camera measures 4.35 x 2.77 x 1.76 in, which is a bit bulky for a pocket camera, but it will fit in baggy pants pockets in pinch. Otherwise, the camera ergonomics are quite good; it fits very comfortably in your hand, and the buttons are well placed.
The camera is powered by AAs; Canon ships it with two throw-aways, which according to CIPA standards should net you 220 shots. CIPA for rechargeable NIMH batteries is officially 450 shots. I bought Sanyo Eneloop pre-charged (aka slow-self discharge) NIMH batteries (2 kmAh), which out of the box allowed me to take 370 photos and a 1 minute movie. Supposedly the eneloop batteries get better after a couple uses, so 450 shots per charge isn't completely crazy, but I didn't use the flash almost at all, which I'm sure increased my battery life a bit. Note that you can get higher mAh batteries (up to 2.8k mAh), which in theory would allow more pictures per charge, but regular NIMH battery have a high self-discharge rate (20% in the first day, and ~1 percent each following day) so the low-self discharge batteries (which top out at 2k mAh) are probably going to get you the most shots on average unless you plan to take more than 200 shots a day (hey, why not!).
Images can be stored on a SD/SDHC Memory Card, MultiMediaCard, MMC Plus Card, or HC MMC Plus Card. Canon plays a little 'joke' on you and provides a 32MB card with the camera. Might as well find a needy landfill for that one, and get something in the multi-gig range (4GB is a nice size, and lets you record up to 32 minute 640x480 movies).
Usability
The flash flips out from the top of the SX110, which is done manually before you want to use the flash. This is nice in that it prevents you from firing the flash by mistake, but does mean more hassle when you do want to use the flash. Even worse, it takes a really long time to charge the flash - I'd estimate about 5 seconds. Apparently this is the downside to using NIMH batteries, rather than a proprietary LiON battery. Frankly, I don't like the unnatural colors that flashes generally give to photos (this is true of most cameras, not just this one), so I don't care that much.
The interface for the SX 110 is really well thought out. It uses the same standard Canon menu system that I've seen on Canon cameras since the start of this decade. When in auto mode, the menu system gives you very little control, but flip the mode dial to Program, and you can set white balance, metering mode (evaluative/center/spot), resolution, and compression ratio, all with a very minimal number of button presses. In addition there are buttons dedicated to EV (exposure compensation), focus (macro/distance/manual), ISO level, Face detection (sets the autofocus to any faces in the scene), flash, and timed shots / continuous shots.
The program mode is common to most, if not all Canon cameras. What's really cool about the SX110, however, is that there is also a Manual position on the mode dial. Here, you can set the aperture size, the focus, and the exposure time. You use one button to cycle between each option, and then then you a dial you can rotate to quickly set each option's level. When setting the focus, a zoomed in view is shown in the center of the LCD so you can accurately judge focus. While in manual mode you can also set the flash power to 1 of 3 levels.
An interesting compromise between Manual and Program is the aperture and exposure time modes, where you control the respective named setting, and the camera selects the most intelligent value for the other setting (eg if you want to make sure that the exposure time is just 1/5 of a second, the camera will then choose the best aperture so that the image is properly exposed).
Once you've taken the picture, the SX110 automatically switches into review mode, which shows the last photo taken for 2 seconds (this can be set to anything between 0-8 seconds, or infinity). One option in this mode is to have the center of focus blown up to actual pixel sizes, so that you can assess from the LCD how blurry or noisy the image is. This is really handy. While in review mode you can also zoom in on the image to check out other parts of the photo, in addition to the center of focus).
Unlike other Canon cameras, there is now a dedicated button for switching into playback mode (ie you don't have to rotate the mode dial to switch to playback mode). This is really nice if you want to quickly check the quality of the last few photos you took. I much prefer this to how the other more compact powershots work.
One other nice feature of the interface is that you can set one of the buttons for custom use. The list of things that you can do with the custom button is a quite limited - I assign it to turn off the LCD, but there are other options which might interest you, such as one-touch custom white balance, and turning on a grid overlay for aligning your shots. Note that the turn of LCD feature is a bit broken - if you so much as rotate the camera, the LCD comes back on. But you can use it to save battery life in the situation that you are just sitting, waiting for a good shot.
Performance (temporal)
The SX110IS turns on very quickly - the lens is extended in about a second, and you can go from power off to taking a picture in less than 3 seconds. If you want to rapidly take pictures, you can switch the camera into multi-shot mode, where you can hold down the snapshot button and every 1.2 seconds a new photo will be taken - or if you tell the camera to only focus on the first picture, a new photo will be taken every 0.7 seconds. This is a good feature to use when trying to capture rapidly occurring events, or when trying to take a low-light pictures where you have the time to take 10 pictures and then sort thru them to find the one that is the clearest.
Focusing seems to be quite quick - only rarely does it take more than half a second to focus, and usually it focuses almost instantaneously (which is to say, too quick to notice).
The review continues
So that's the basic specs, and how the camera handles. What about image quality, etc? Click here for the rest of the sx110 review, and, eventually the conclusion.