The work at Tower is interesting and challenging -- but you can find work like that at a lot of companies. What distinguishes Tower is the people and the office. The people are young (the majority in their twenties) and friendly and outgoing. Management is laid back, gives ownership of serious projects to new grads, and encourages new ideas for projects. Everyone is approachable. All call each other by first names. The office is a wonderful loft space with a private roof deck for eating lunch, having parties, or hanging out. There are three snack and drink stocked kitchens at our disposal. Breakfast and lunch are brought in every day. Sometimes we cook for each other. Tower has few rules and policies beyond the unstated expectation that everyone should act respectfully toward each other. There are no suits at Tower. It's like grad school -- but it doesn't suck. ;)
I graduated from Stanford in 2007 with a masters in computer science.