I know this question on recommended phones for Asterisk have been asked before, but another criteria I would like to add in would be :
(1) The ones that allow you to push telephony applications onto the phone easily. e.g. , on the Cisco 7970, you can dial in a number and later have an XML-encoded menu pushed to the phone so it has a feature-rich GUI app. I plan to look out for cheaper alternatives than the 7970s
(2) The ease of configuration to make the phone work for Asterisk. e.g. , almost all Cisco phones require you to do a SIP firmware update which is very cumbersome
(3) Are there wireless VOIP phones that you recommend for Asterisk? The only one I have heard of is the Linksys WIP330 which I am not sure works with Asterisk.
I will be using Asterisk 1.4 with FreePBX on an Ubuntu system