I've been picking up tig welding. I started by doing around 200 practice welds (1 or 1 1/8" welded to 1 1/4" at a 73 degree angle, approximating a top tube to a head tube) before I tried to build a bike with it.
Here's a picture of my first (tig'd) bike. This is my daily commuter/fixed gear.
With integrated rack
The rack was added later as evidenced by the rust/no rust finish. I'd had enough of the messenger bag sweatback.
Here's the bike after I finally had it powder coated off-white. I originally had planned to leave it raw metal because I figured it would only be a summer bike and the rust wouldn't be a big deal. However, when I tried to get back on the rain commuter bike I had ridden before this bike I hated it and got this one powder coated so I could ride it year round.
Here is what some of the many practice weld pieces became. Night lights!
