I tried out a friends pocket pc (or is it windows mobile now?) smartphone recently - a cool little device with a slide out QWERTY keyboard (I think it was a variation of this htc device). It also had wifi support so I thought I would try to blog from it. However, he hadn't got opera installed and the wordpress gui completely failed to work in pocket internet explorer. I'm sure there is a solution to this, but I was disappointed that the wordpress online admin didn't gracefully degrade.

This is something to consider when designing web apps - whilst AJAX could potentially be used to provide huge usability enhancements to people using mobile web devices with small screens - the majority of people are going to be using windows mobile with pocket internet explorer - your app should work with no javascript support at all. and then be progressively enhanced with AJAX as a seperate consideration.