Jxc,
I recently bought an iPaq PDA specifically for use as a GPS and bought a copy of Memory Map's CAA 1:500,000 VFR Chart, which was £20.
http://www.memory-map.co.uk/maps_uk_intheair.htm
So this gives you your CAA chart on your PDA/GPS. I have no idea whether this software would work on your Nokia E90? But it's definitely worth looking into.
Cheers.