I got some exciting news last month - both the Guardian and the Economist have been busy digitising their backfiles, and are about to launch online archives. The Guardian Digital Archive includes the Guardian from 1821-1975 (1976-2003 will be added next year) and the Observer from 1900-1975 (but - exciting! - from next year will go back to 1791).
The Economist Historical Archive covers 1843-2003 and will be available from December. I actually got to see a beta version of the Economist a while back and offer some usability feedback (nice customer service touch from the sales rep, I thought).
Anyway, the Guardian is offering free access during November and it's worth having a look. You have to create an account and register for a 24 hour 'timed pass', but once you've done that you can view, print, and email images aplenty.
Renée (Digital Resources Librarian)