Oh Yeah! is awesome - free WiFi, fair trade coffee, vegan and non-vegan(Dave & Andy's) ice cream, gluten free(and non-gluten free) waffles.
The centerpiece of Oh Yeah! is their ice cream mixing machine - top a scoop with whatever you want - literally, they have a ton of mix-ins - and they'll run it through the machine and swirl it all up. The waffles are decent, but I think they're a little pricey for being just that - a waffle.
The coffee is only a buck if you bring your own mug, as well.. it's a steal. The staff is also super friendly and don't miss out on the glass-door bathroom. Your friends can't see you, don't worry.
My biggest concern about the place is allergies, though. I once went in with my brother who is very allergic to nuts. The girl offered to clean the swirl attachment with water and we asked if they could use a little soap, then water to be safe and she said she wasn't sure. I understand this, but I wish they kept a clean attachment or two on the side for allergic people - the last thing he needs is the remnants of someone's peanut choice sneaking into his ice cream to send him to the hospital.