I'm new to the iPhone and iPod Touch, so please let me know if I'm missing something obvious... but I just found that one of Apple's Web sites -- a site targeted to iPhone/iPod users -- crashes the mobile browser. (I have already reported this problem to Apple.)
Here's the deal: I got my new iPod Touch yesterday, and in the course of trying it out I opened the App Store app and went to download a free app. I was asked for a username and password, which I did not yet have. I wasn't sure where to go to get one -- iTunes? So I just googled App Store and clicked the first link, which was this:
http://www.apple.com/iphone/appstore/

The iPod worked for about 30 seconds, and then Safari crashed -- I was unceremoniously returned to the home screen. I tried it again -- same result. I tried it on the iPhone Simulator on my Mac and got the error message at left, which is how I reported it to Apple.
I'm sure I'll figure out how to register for an account soon and be on my way, but for now I'm just glad that our own site doesn't have this problem!
Otherwise, I'm very impressed with the iPod Touch and look forward to having more to say about it soon.