Palm TX VOIP headset adapter

That actually looks pretty good. But then again, I'm lazy, so for those of you not interested in rigging up your own adapter, theheadsetbuddy.com has all sorts of different adapters (don't think they have the one you made). Here are a few: PC headset to palm adapter or smartphone/palm headset to pc adapters. They have a few more but you get the jist.

Daigle

What if I only want a jack input ? Would it be possible to install a 2.5mm Jack for hi-z instrument input ? Say, a guitar ? Maybe only a pre-amplified guitar ? I'd really like to be able to do that, can somebody give me a gentle nudge in the right direction ?