I've been asking around at the bike shops in the Boston area about cup holders, and oddly, nobody seems to know if any of them will properly fit the typical Dunkin cup. Unfortunately, since I lack a cup holder, I haven't easily been able to stop into a shop with one of those cups, so I was curious if anyone here had any experience with that.

Before someone suggests that I just get a thermos and bottle cage, I'd like to point out that I don't stop for coffee every day that I ride into work, and sometimes that's a spur-of-the-moment decision, so I don't feel that it would be convenient to need to remember to carry a thermos constantly.