No, it's not because Jeff Garlin and Mary Lynn Rajskub have become so incredibly famous that fans might mob them at a Starbucks or something. It's because they joined the internet meme turned movie Safety Not Guaranteed.

Also starring Aubrey Plaza and Kristen Bell, Safety Not Guaranteed is the kinda true story of a man looking for a partner to time travel with, and the three magazine staffers sent to investigate his classified ad. The film is directed by Colin Trevorrow, from a script by Derek Connolly. No word on who Rajskub and Garlin will play, though if I had to take a guess... a socially awkward computer worker and a fat guy who gets yelled at by his wife. Just going with my gut.

Safety Not Guaranteed began production in April. (Hollywood Reporter)