The latest conference: m-Learn 2006
There is not much in the way of full papers on the web, you need to search a little.  There is another m-learning conference early next year.

There is a list of a lot of web 2.0 apps in a wiki based at CPIT which contains a list of m-learning tools.  A little daunting.  The list is managed by Selena Chan, and her blog on m-learning at http://mportfolios.blogspot.com/ and her links there is probably as good an introduction as you will get, and a feed will keep you quite current.

I’m interested in the open source options that allow you to text or pxt into your personal space.
Sakai is just one open source Learning Environment type product I have heard that has mobile connection for students: SMS (Texting) to and MMS (picture from cell phone) to a personal learning space.  I’d be interested in anybody who has used this.

There are definitely educational situations where this facility could be really beneficial.  Here is Selena talking on Blip.tv (courtesy of Stephen Parker)