These guys have set up a just giving page in memory of Elisabeth Sladen with all money going to cancer research. Originally they were aiming for £500, but the seem to have passed that a few hours past. Anyway, personally, I think its a nice idea and thought I'd pass on the link here incase anyone else thought so too.
http://www.justgiving.com/inmemoryofelisabethsladen
http://www.justgiving.com/inmemoryofelisabethsladen