A recent self post on Hacker News asking "How did you choose a name for your startup?" got me all nostalgic, so I thought I'd share my response:
We knew the site would involve reading what's new online, so I would spend classtime thinking about domains involving something like "read." It was also during this classtime that I first doodled the alien in the corner of a notebook.
I was in my beloved Alderman library when "reddit" came to mind, as in "I reddit on reddit" (although this slogan was courtesy of PG). I'd also registered reditt because I couldn't decide which one was better. Granted, I was worried about how poorly it was spelled, but it seemed easy enough to remember.
For a time, it was just added to a long list of potential names. We spent the first month of YC without a confirmed name, but I always stuck with reddit despite being repeatedly told how terrible a name it was :-)
Finally Steve acquiesced and we went with reddit. This was after wasting a solid 2 entire days just hunting for domains -- not a great use of time, I must say.
It was also before instantdomainsearch, which I highly recommend.