I have one of these that works well. I bought it mostly because I wanted a small-sized mug--my occasional purchased coffee of choice is an iced 3x espresso, and that was completely lost in the usual 16 oz ++ mugs, plus I could easily drink way too much coffee and my stomach is less than thrilled about that after awhile. They come in bigger sizes/other colors as well.

It keeps things warm/cool reasonably well (not nearly as well as my steel thermos, but I don't generally like super hot coffee anyway) and I carry it (full of coffee) in a pannier almost everyday....I usually stick it in a big ziplock just in case, but nothing has ever leaked.