Confoosed and Confuddled --

So I'm getting myself a digital camera. That much is decided.

Which one do I get? That's where the fun starts --

I've been reading about them for the past few days and I've decided on the following criteria:
1. AA or AAA batteries -- I don't want the hassle of charging lithium batteries.
2. 5 megapixels and up. ~~Oh the lure of a 10 megapixel camera~~
3. $200 and under
4. Durable -- it must last as long as my dinky cybershot. What worries me is that newer digital cameras are made mostly of plastic and I don't know how long it will last me.
5. I'm leaning towards Sony because I'm used to the system but my brother is a big Canon fan.
6. Light/small enough that I won't mind bringing it everywhere with me.
7. It must look pretty ^_^

So I've looked and here are my choices (prices from Amazon.com)--
1. Canon Powershot A530 - 5 megapixels for $149.99
2. Sony Cybershot S500 - 6 megapixels for $149.99
3. Canon Powershot A540 - 6 megapixels for $177.00
4. Sony Cybershot DSCW50 - 6 megapixels for $199.99
5. Sony Cybershot DSCW30 - 6 megapixels for $174.99

Oh, and my dream camera? Canon Powershot A640 -- it looks pretty ^_^

Which one should I get?