I never was really happy with my TLA as nickname -- but well, thl (from Thorsten Heiner Leemhuis oder Thorsten Leemhuis) was the thing that sprung to my mind when I needed a nickname for IRC. I actually tried to think about something else quite a bit of time back then, but I didn't find something better that was free, so I just started using thl.
But recently I thought again to look out for something else -- IRC once again was the trigger, as thl was owned by someone else on OFTC already (and there was actually somebody else on freenode that tried to use thl these days). So I searched for something else.
I considered "steinlaus" (Petrophaga lorioti), but that joke is hard to understand for people outside of Germany (I'm actually wondering how many Germans will understand it these days), so I took something more international.