Me too Les, I love my Desire, it's the second HTC I've had and will be upgrading it to the Desire HD in a couple of months. I took my phone and laptop on my recent trip and didn't even bother switching my lap top on. Everything I needed to do could be done on my phone.
I've asked my phone provider about virus' and malware, they informed me that as an 02 business customer I automatically get full protection. I've been using WAP enabled Nokia's, BB's and HTC's for about 6 years and have never had an issue with anything dodgy.