I've been following VA Linux' (LNUX) Slashdot and Sourceforge traffic since I first purchased LNUX in late July.
To see Slashdot's historical traffic, you change the range parameter of the URL of the two year chart from "range=2y" to "range=5y". See below:
- Range = 2 Years: http://www.alexa.com/data/details/traffic_details?&range=2y&size=large&y=r&url=slashdot.org
- Range = 5 Years: http://www.alexa.com/data/details/traffic_details?&range=5y&size=large&y=r&url=slashdot.org
I added Digg.com as a comparison. Interestingly, traffic has surged at Slashdot around the same times that Digg saw big increases in traffic. My theory is that press coverage of Digg and user-generated content has lifted the interest in the old school Slashdot. The Digg effect seems to have vaulted Slashdot to new heights but also underscores the impressive growth of Digg, surpassing Slashdot's historical traffic highs in less than a year!
Full disclosure: I own LNUX shares at the time of writing.