About a year ago I expected that my future iPhone would be joined by the Bose QC 2 mobile communications kit. The kit adds a microphone to Bose QC 2 headphones, so it's possible to use the phones during calls.
... the $40 Bose QuietComfort 2 Mobile Communications Kit. Sure, it's much more expensive than whittling, but it includes a microphone so you can handle incoming calls. On the other hand it only works with post-2005 QC2s ...
I later read that the pre-2005 QC 2 incompatibility was due to an easy-to-remove plastic protrusion. On the other hand, the Apple Store reviews tell us there's no answer/pause button on the Bose microphone.
The Bose kit is fairly elegant looking however. It replaces the standard cord, so there's no cord clutter.
Later I saw a Griffin kit that worked with any set of headphones, had an answer button, and cost half the price. That sounded right -- but it's gone now.
In its place is the Monster iSoniTalk. It was designed for iPhone 1.0 (fits the recess), but works fine with iPhone 2.0.
I agree with the 1/08 review -- it's really pretty good. Costs $20, seems to work well, decent microphone and clip and it has an inline answer button on the mike (like Apple's set). It does create cord clutter; I'd prefer a serial connection with no double cord rather than the iSoniTalk's parallel cord (see pictures in linked review). The splitter by the phone connection is pretty big and ugly looking too.
So get the QC 2 kit if you have the Bose headphones, want minimal cord clutter and a svelte connection, and don't mind answering calls using the iPhone (not a big deal for me). Otherwise, the iSoniTalk is fine. I'm looking forward to trying it with my next conference call.
Update 8/21/08: Turns out these are weird to use. When I wear the QC2 heaphones, my own voice is distant and muffled. The headphones don't play back my own voice.