I don't know if this counts as a conversion or not. 2005 Trek 4300 MTB - changed out wheelset to get 36 spokes, added rear rack, Delta Shock Treatment front rack, B-17, Crankbrother Candy pedals, trekking bar and sacrificed a cheap lunchbox for a handlebar bag. Nashbar Compact Euro panniers on the rear, LonePeak on the front. This bike is intended for paved roads, gravel roads and non-technical single track travel, so I left on a low profile knobby tire.
I will say that if I had larger rear panniers or bigger feet, I might have problems with heel strike, but this is turning out to be a pretty fun bike and it really handles better loaded than bare. I can no hand it for miles loaded, but will fall within about 10 feet without a load.
I will say that I envied this set-up after about 70 miles under my own power.
