Recently, I've been dinking around with perl ithreads (in 5.8). Last Tuesday, I gave a perl ithreads overview presentation at the local Perl Mongers' technical meeting. For the talk, I hacked up a basic chat server to show how threads more or less worked in perl (it basically just echos what one client sends to every other connected client).
Since then, I updated my nsrev utility to use Net::Netmask and ithreads to quickly scan DNS PTR records for a specified section of the Internet. Right now, I'm scanning APNIC and RIPE space, in a month or two, nsrev will finish, and I'll be able to pick over the address space to see what it looks like and possibly to add some of it to our local anti-spam RBL(Real-time black list of IPs our mail server should not talk to).
Receivables. Can't live without 'em. FSST has 'em in the amount of 20% of sales, ELNK has them at about 4% of sales. AOL has 15%. In other subscription based businesses, GCI has it at 1.5%, TRB at 14%, and PRM at 15%. Such variance is astounding.