Hijacked

My blog got hijacked.
The Sagittarian alerted me to the fact.
When you went to my url, it flashed the blog up for a second, then went to some random blog setting up site (not blogger).
EEEEEK!
Happily I was able to fix it, with some help from those people who's answers came up after a trusty google search. I was able to delete the offending code in my setup. I deleted some good things while I was figuring it out. But how did that nasty code get in there???
Double eeeeek!
I have now changed my password too......I hope it doesn't happen to you.