I use Bluetooth for my laptop to talk to my cellphone, but I've usually had to spend a fair bit of time to get Bluetooth links to work (laptop, iPaq, several cellphones, BT headset, and so on). I wouldn't want to be doing that in these cases.
I use the USB-USB cable mostly for dealing with friends' PCs that have been infected with viruses - first, to upload virus removal software, and second to download key files to my machine to try to unscramble them. Until recently, it was the work of a minute to install the USB link software and get the FTP set up. Now, it just doesn't work.
I'm hoping someone, somewhere will say "Ah, it's an incompatibility in XP2 grot.sys; you need to download patch XXX from YYY." No joy yet, though.
Or for someone to say "There's a new piece of software called xxx that will do the job - remove the old one and install this".