30 Rock won’t be back till mid-season, but Alec Baldwin has kindly come along to bridge the gap. Yes, the sometime HuffPo essayist plunged into microblogging and joined Twitter this week! He began tentatively (“Maybe I needed a glass of wine beforehand. I feel … so shyâ€) but by yesterday, Baldwin had already mastered the format to make jokes at Steve Martin’s expense: “My friend Steve M is an art lover, a thespian and plays music. Or, an arthritic.†Maybe he can set an example for his 30 Rock co-star Tracy Morgan, who famously gave in to demands that he join Twitter in 2009, but has posted a scant 30 times since then. [Alec Baldwin/Twitter]