Guilty here as well; I commuted by bike on geared bikes for decades but as soon as I started reading BF I decided to try out the singlespeed/fixed thing. Converted my RB-1 and tried it as a singlespeed first then flipped the wheel after a few days to fixed. Liked it so much I bought a Panasonic DX4000 off craigslist for cheap ($60.00!) and converted it to full-time fixed commuter usage so I could put the RB-1 back to weekend roadie. Also built up a singlespeed townie (old Centurion) for wet weather commuting and grocery shopping and converted my wife's MB-3 into a singlespeed (she loves it because she hates dealing with shifters) winter beater. I rarely reach for my Crosscheck for the commute and it's brand new!

Now I am waiting for the BF IRO frame so I can ride a more purpose-built machine. Damn you, BF!