A video piece on CNET caught my interest recently - a search engine that could recognise faces and text in images. When I decided to check it out I discovered that because the developers had chosen Ajax for their UI there were issues with cross browser/OS compatibility - Safari users need not apply right now.
Browser detection locked me out of a front page that on face value doesn't contain anything tricky - it's funny really.
If your application is using a lot of graphical trickery, doing nice UI stuff, and you're trying to reach the maximum number of users - why use a technology that'll lock people out?
The Riya Safari welcome message is below: