A long time ago I bought "Network Programming with Perl" by Lincoln D. Stein. I remember reading it cover to cover - I'd just lost my job and I had time to spare. I lent it to some one in my LUG a few weeks ago and he gave it back at the weekend.
It's a book I should read again. When I read it the first time I didn't run a POSIX system full-time and ActivePerl just couldn't do what Perl on Linux/Unix could at the same time. Now I run Linux at home almost exclusively and even at work I use Linux/AIX quite a bit despite IT's love of Windows. I don't have an excuse to try out more of the code now.