The house today
29 Arlington Avenue is a house in Islington, London. Douglas Adams shared the house for a time with Jonny Brock and Clare Gorst. It is mentioned in the dedication of The Hitchhiker's Guide to the Galaxy, which is dedicated to the "Arlingtonians for tea, sympathy, and a sofa."
The phone number of this house was 226 7709. In The Hitchhiker's Guide to the Galaxy when Arthur Dent and Ford Prefect are rescued in ZZ9 Plural Z Alpha, the probability of that happening was 2 to the power of 276,709 to one against. This is also noted to be the phone number of an Islington flat where Arthur met Trillian and Zaphod, or "Phil", as he then referred to himself, at a party. Coincidentally, this is the same party that Trillian left the Earth with Zaphod.[1]