To be honest, in that price range most of the cameras you look at will be very similar. They will all have some shutter lag, and most of them will probably have similar quality. Unless you start getting in to the more advance and higher priced cameras, will you start seeing a large difference. But that doesn't mean they're all the same. Best way to decide is to physically go and compare them side by side, and decide which one you think is the most user friendly. Once you start getting an idea of what you want, you'll start to find out which ones will stand out.

Some of the main things you might want to consider

1) Resolution - This is how they catagorize most cameras, by how many megapixels it's capable of. There are some general rules as to which size you should get based on your needs. If you will strictly be e-mailing photos or looking at them on a computer, you can get by with 1 MP or less. However, once you start printing them out, you'll want at least 3+ MP. The higher end cameras with 6-10 MP are good for poster size prints. Now even if you don't ever think you'll print pictures that size, don't forget you can use that extra resolution to zoom into one area of a picture and crop the rest, so the larger resolution gives you more options. By deciding how much resolution you need, that narrows down your options quite a bit.

2) Batteries - Either AA or proprietary. Your choice on this, some people like having common AA, some people don't care. The advantage of AA's is commonality, you can find them almost anywhere, but it comes at a price of size and weight. You won't find any really small sized cameras that take AA, the batteries themselves are much bulkier than the specialty batteries. Also, even though they might take AA's, most of the cameras drain regular alkalines really, really fast, so you'll most likely want rechargables. Aftermarket batteries for most cameras are pretty cheap (probably cheaper than AA's) on ebay, so that gives you another options. I've had ok luck with aftermarket batteries, sometimes they work fine, other times, well, I know why they're that cheap. I like the idea of using AA's, but I also like having a more pocketable camera so I'm willing to make the tradeoff.

3) Internal memory - If you can find one with internal memory, it's well worth it. Internal memory gives you a buffer for the pictures, so it doesn't have to wait for each picture to finish writing to your memory card before you shoot the next one. The camera can write to the internal memory much faster than it can write to the memory card, so you can shoot a few pictures pretty quick and save it to the internal memory, and when you're done shooting, it will transfer that data to the memory card at a slower rate.

4) Shutter lag - in that price range, most all of them are going to have shutter lag. It is annoying when you are trying to capture a candid moment, but other than preparing for it, there's not much you can do other than getting a higher priced camera. Some cameras also have a "picture" lag, the time it takes between shots. Internal memory helps with this, as does turning off the flash so the batteries recharge quicker.

5) Zoom - just focus on optical zoom specs, don't even concern yourself with the exaggerated digital zoom specs. By the time you zoom in 50X with digital zoom, you're going to be looking at an unidentifiable mess. Also, anything more than 3X zoom

6) Memory - As someone else mentioned, Sony uses their own brand of memory and batteries, so aftermarket items for their stuff is limited. That means you'll be paying higher for the accessories. Just something to keep in mind.

Once you know what you're looking for, it's a whole lot easier to go to the store narrow your preferences down. Also, before you go to the store, you might want to research a couple of your top choices. Every company has some quirks or problems that you might want to find out. Canon has their E18 error, Nikon has some picture quality problems, and I forgot what problems Sony has. Doesn't mean you'll have those problems, but it's better to know in advance what to expect just in case.