The School of Industrial Management (Escuela de Organización Industrial EOI) in Madrid is issuing students with 3G Android mobile phones and using the Moodle learning management system (English translation and Spanish original). This looks a good combination. I found that my Moodle course notes for a Green ICT Course worked fine on a Google Android. This was because I made use of the Moodle "Book" module, for
the course content. This produces plain web pages, which render well on the small screen of smart phones. Of course if you used very large and complex PDF, Powerpoint, Microsoft Word or other formats, it would not look so good.
There could even be some problems with ordinary HTML (I am trying to convince one of my fellow course designers not to use very large complex tables in course notes. These tables are hard to read at the best of times, but make accessibility and mobile access very difficult.
While I didn't try it, podcasts should also work well. Obviously typing a 2,000 word essay on a smartphone would not be a good idea, but participation in forums should be feasible. Some changes to the Moodle user interface would be useful, as it does use HTML Table statements for some layout, which does not adapt well to a small screen.
I was handed the Android at Google's Sydney office, when giving a talk on my Green ICT e-learning course and only had it to try for a few minutes, so this was not an exhaustive test. Also it was running a beta version of the operating system.