Nokia 6682 / 6681
No 2.5mm jack?!
and the microphone (switch) is easy to "unscrew" and mod
http://www.stewartb.com/nokia-mod/ »
Also a company has produced a nice alternative to mod-ing your headsets
Search google for these words "Skullcandy, pop-port"
You'll find a few variations from Skullcandy. All seem good.