Forget all the big chain Hyatt-Regency stuff: Irving House is a lovely little Victorian guest-house that's about ten minutes walk from Harvard Square, and not far from MIT. The rooms are a bit folksy and pleasant. The breakfast room is what you'd expect. If you are prepared to not have an en-suite bathroom, you can stay less than $100 a night, which is Travelodge sort of money in pounds. There's lots of books and for the geeks there is free wifi throughout.