Ok, I got permission to share the traffic and hit counts from Edward Tufte's site during the Slashdotting. The 13th is the day before the site was mentioned on Slashdot is represents their average traffic.
13/Dec/2003 Hits: 68.7k, Traffic: 1.10 Gigs
14/Dec/2003 Hits: 457.8k, Traffic: 7.81 Gigs
15/Dec/2003 Hits: 436.8k, Traffic: 7.41 Gigs
16/Dec/2003 Hits: 228.4k, Traffic: 3.92 Gigs
17/Dec/2003 Hits: 209.2k, Traffic: 3.60 Gigs
18/Dec/2003 Hits: 155.7k, Traffic: 2.49 Gigs
19/Dec/2003 Hits: 135.5k, Traffic: 2.08 Gigs
20/Dec/2003 Hits: 52.2k, Traffic: 0.82 Gigs
This isn't an especially large event, but it's interesting in that the event lasted much longer than a typically Slashdot event. On other sites we host that have been slashdotted, the traffic has been a bell-curve shape with a single peak.
Here, the peak traffic on the 14th and 15th was at around 2 PM EST and had a substained data transfer of nearly 4 Mbit/sec.
We don't monitor response times, but the site never went down and the load on the server never exceeded 4. As luck would have it, this is our least powerful server -- it's a Dell 2450 with a single 733-MHz PIII CPU and only 1-GB of RAM. It has 4 18-GB SCSI drives on a hardware RAID 5 controller. It's a shared server and hosts a few other sites in addition to Tufte's.