Either this is a new feature, or I totally overlooked it. Either way, this is very cool.
Flickr has a calendar view of your photostream - showing when photos were taken or posted. What an easy and powerful way to see what you've done (and where you've been) in a given 5-week period.
In this calendar view, I can see when I was in Vancouver for MW2005 (the blue sunset on the 13th), went hiking with Evan on the 17th. Got the new camera and tested it out on the 23rd, and went to San Francisco and Rohnert Park for the Pachyderm Pow-wow from the 25-27th. A month at a glance!