It helps when one works in a company that does business in computers (Citrix Metaframe, Proxyservers, SAN-solutions and so on). This almost automatically means that everybody has PC's on their desks. Also this mostly means that there are 2 or more test-labs with servers/desktop PC's. Those machines aren't used all the time, so... When I started here I was one of the administrators and my fellow administrators didn't mind letting me use the PC's/servers for RC5 as long as they didn't interfere.
There are also weeks when a new serversystem of a customer arrives here. That means building the stuff from bare metal up to...whatever. Most of the times we let the stuff standing here running for testing or installation work. At the moment the customer needs the stuff I delete all RC5 things and clean up the registery (since DNET puts a value with key there).
The latter of possibilities described above doesn't help that often, but if it does...it party-time!
PS it also helps to check if certain 'old' systems are still being used or just standing there without power. It doesn't mean that much if it's a P2-200 or so. If you've got 5 of them then you've got another 1Mkey/s of power