Short notice tonight, but wanted to let you know of comedians appearing this week on Late Show with David Letterman, the only WGA-approved late-night show of choice.

Tonight: Frank Caliendo shows his impersonations and explains his TBS show. Tuesday: Don Rickles plugs the DVD release of his documentary. Friday: Jim Gaffigan will likely mention bacon!

Conan and Leno aren’t putting their guest appearances online so as to avoid picket-crossing hassles, but I’ll keep my eyes peeled. Saw Elon Gold on Leno the other night. Christopher Titus, too. Conan, meanwhile, has really been upfront about mentioning the plight of the striking writers and about killing time. I saw him devote a full 10 minutes to a hilarious pre-taped segment interview with one of his producers. Then again, past episodes of Conan can be viewed on the NBC site online. Which is at the heart of the WGA negotiations. Also will be keeping you updated on goings-on with Jon Stewart and Stephen Colbert, so don’t you worry.