Android has such a large "mind share" in the Open Source community that I forgot how much it is still flying under the radar. So far it is only on one phone, see
Using the T-Mobile G1 as an eBook reader but Android is seen as a major potential competitor to iPhone. There are going to be lots of Android smart phones this year, and also Archos is developing an
Android phone / tablet. See also jayakumar's initial port to EInk in
Znet suggests Kindroid (Android on Kindle).