atmega168 eagle file?

Just use the mega8 that is included - it's exactly the same except for the name.

Alternatively a search for "eagle library 168" gives me a suitable library on the first search item - it's on Cadsoft's (the makers of Eagle) downloads page

http://www.cadsoft.de/cgi-bin/download.pl?page=/home/cadsoft/html_public/download.htm.en&dir=eagle/userfiles/libraries