A new report from Royal Pingdom reveals that Twitter unsurprisingly led social networks in downtime for the first four months of 2008 with a total of 37 hours and 16 minutes. The good news is that even with all that downtime, that’s still a 98.72% uptime percentage for the first third of the year — which isn’t terrible. Can we really complain about a free service thats “only” up nearly 99% of the time?

The next closest social network on the list in terms of downtime was Reunion.com, which was down about half as long as Twitter. Pownce, a Twitter-like microblogging service from Digg founder Kevin Rose that added file sharing and group direct messages, also suffered more than its fair share of downtime over the first few months of the year. The social network that has suffered the fewest outages? MySpace — just down 1 hour, 5 minutes so far this year.

Twitter wracked up the most downtime during the months of January and February, with 13 hours each. Interestingly, its best month was March, when a lot of people expected heavy tweeting from the SXSW festival would bring Twitter down. Both Twitter’s lead architect and VP of engineering left the company last month, which many bloggers assume was in direct correlation to its infamous downtime issues.