Obvious I know, but I never If you value your data and the time you spent 'building' up and customising your phone and apps etc. then:
TAKE A REGULAR BACKUP !! ... do it now !

If you have a N900 then there is a good possibility that the usb data/charging port will become loose or detach and you'll have no means to access your phone/data/apps and with Nokia possibly offering a replacement handset under warranty and you losing everything.

Thankfully I found a local Nokia Service Centre who re-soldered the micro USB for 25UKP and had my phone available the next day.

Happy to have my N900 back and working, but unhappy with Nokia' s poor design on the inadequate securing of the heavily used micro USB socket.