The entire lab is firewalled by IPCop 1.4.10 running on an elderly Dell Optiplex GX110. It's a very small footprint workstation-class system with a PIII 667Mhz CPU, 128MB of RAM, a few 10/100 NICs and a CF-to-IDE adapter with a 512MB CompactFlash card. No moving parts other than the CPU and case fans, and voila, a stable, reliable, configurable, open-source firewall. IPCop really is extremely easy and featureful. Currently, my IPCop box is doing some rudimentary QoS for SIP calls, providing an OpenVPN endpoint for when I'm on the road, and running several nailed-up IPSec VPN connections to a variety of other gear, including PIX firewalls and SonicWall firewalls. This system has been in place for five years now without missing a beat. I even had time to put together a gkrellm package for IPCop to let me watch network I/O and stats on the firewall in real-time from my workstation.
Racks, PDUs and UPSes
American Power Conversion (APC), all the way. The abuse that the racks in the lab receive is generally far beyond what any normal production infrastructure would endure, with servers being racked, unracked, and re-racked on a constant basis. The APC enclosures that I have in the lab withstand all of that without even a scratch (really). There's plenty of sidewall cable-routing space, and the 0U networked PDUs make remote powercycling simple.
The UPSes are all APC as well. I don't have a hard-wired UPS, so the lab is served by several SmartUPS 2200XLs and a few smaller units. I do have several dead UPSes still hanging around, including a few older APC models whose batteries gave up the ghost, but the Tripp-Lite unit is a doorstop now, even though the batteries aren't dead, as are the lower-end Belkin units. In addition, when the generator kicks in, it tends to produce occasional harmonics in the lab power service, which none of the other units dealt with very well. The APC units would trigger alarms during these instances, but with the easily-adjustable sensitivity control at the rear of the units, it became a non-issue. Also, the SNMP support is great, providing my Cacti-tweaking habit with plenty of fodder.
As far as the generator goes, it's a Guardian LP unit, straight from Home Depot, with a 200 amp automatic transfer switch. It's saved my bacon several times, though it hasn't been called into service in 10 months or so. Winter's definitely coming, however, and so I have every belief that it'll see some action soon. In the interim, it runs weekly 10-minute exercise cycles that have been keeping it in shape.