I upgraded to the OCZ GameXStream 700W SLI Power Supply from my trusty old 500W Antec, which just couldn't cut it anymore due to these ever increasing demands from high watt components *cough* video cards *cough*.
This power supply has two PCI-E connectors, which means it is officially an SLI-capable power supply, but not for 8800GTX and Ultras, as those cards require two connectors EACH, so you'll have to search for another brand if you want to go that route. However, if you want to a system with any other two PCI-E video cards that only require 1 PCI-E power connector each, this supply will do the job. Smart consumers would probably aim for two 8800GT's right now rather than 2 GTX or Ultra's, considering benchmark and power consumption results now widely available on the web.
Installation was fairly easy. The cables are very sleek and do help to facilitate airflow, though most PSU manufacturers these days do have more aerodynamic cables than the sloppy ones of the past. At 700 watts, this will power most systems with no problems, even if you have a few hard drives and 2 or so optical drives.