Go for BlackBerry, be a leader not a follower.
??? be a leader??? Blackberry? Nearly every school kid in the country has a damned Blackberry! If you want to realise the true benefit of a Blackberry (push email that works), your going to pay another £5/ month on your contract. Blackberry web browsing is pretty clunky and awkward, also, most handsets are only 2g. You need a touch screen, so your only choice would be a Blackberry Torch. “Follower” is the word that springs to mind when the name Blackberry pops up!
I use a Nokia 5800 3.5g which does the job and suits a more techy person, but i would not recommend them now. I concede that Nokia are loosing the battle of the smart phone.
I’d look at handsets running with the Android platform.
Apple products are seductive with a brilliant UI now, but they cost a fortune, you will have restricted access to content and will be forced to use iTunes. Then there are niggles like you can’t upgrade the memory, or switch the battery if you are out and about when your battery is depleted (and iPhones aren’t renowned for long intervals between charges).
The Nokia N8 is just out and whilst this looks like a decent bit of kit, i’m still not convinced that Nokia have ironed out all the kinks from the early versions of the S60V5 OS yet. Nokia seriously need to pull their socks up and sharpish!