1) Sure, there's the easy stuff, like they suddenly became famous due to appearances on certain TV shows:

Mark Hamill: "David Bradford" on Eight is Enough

Adam West: "Edgar Garibaldi, trapeze artist" on Laverne and Shirley

Dick Van Dyke: "Malduke" on Airwolf

Courtney Thorne-Smith: "Stacey Hamilton" on Fast Times

2) Or there's the fact that their careers are eerily linked via the strange workings of the entertainment industry:

Mark Hamill was the voice of the Joker in the many animated Batman series and films, and Adam West was constantly fighting the Joker in the Batman TV parody of the 1960s. Then Adam appeared on the Simpsons in an episode titled "Large Marge", and Courtney Thorne-Smith was also on the Simpsons in "Who Shot Mr. Burns? Part 2". Finally, Courtney and Dick Van Dyke have both appeared as themselves on the The Rosie O'Donnell Show.

3) http://www.daveschool.com/BATMAN

What you get is all four actors lending their voices to Batman: New Times. It's computer-generated. Batman. In Lego blocks.

The production is really well done. It's entertaining (far more than certain films starring George Clooney or Val Kilmer), visually impressive and has a great attention to detail. They've even managed to give Batman some of Adam West's old physical mannerisms.

...And is it wrong that I found a computer-generated-Lego-block-shaped Catwoman sexy?