Harrison stated in The Beatles Anthology:

"Here Comes the Sun" was written at the time when Apple was getting like school, where we had to go and be businessmen: 'Sign this' and 'sign that'. Anyway, it seems as if winter in England goes on forever, by the time spring comes you really deserve it. So one day I decided I was going to sag off Apple and I went over to Eric Clapton's house. The relief of not having to go see all those dopey accountants was wonderful, and I walked around the garden with one of Eric's acoustic guitars and wrote "Here Comes The Sun".‏¹

http://en.wikipedia.org/wiki/Here_Comes_the_Sun