Got a basic Blackberry that I've suspended the contract on. Is there anything I can do with it without renewing the contract or incuring charges.

I use a SH Blackberry with a old PAYG sim card. It works fine as a 'phone + diary, but obviously doesn't allow any of the fancy web-browsing functions to work.

It will work fine as a phone with any SIM you put in it, including browsing etc. The only thing you won't get get is the Blackberry push email service. That said, the Blackberry is pretty cr*p for everything except email compared to other phones, so you won't have a great device

As above, I bough one secondhand and prior to adding the Blackberry package to my contract it worked fine a a phone, browser etc.