HTC Desire and GPS - how does it work? I'm curious as to how the GPS works on the phone? In particular, what impacts does putting the phone in my pocket/bag have on the GPS signal?

Reason I ask is, I've recently installed the CardioTrainer app on my HTC Desire to record my workouts and I've realised that sometimes the GPS tracking "jumps" a lot - ie. CardioTrainer will record several partial segments during a jog, mainly because I seem to lose GPS signal every now and then.

I've noticed that this generally happens when I put the phone in my pocket or bag, and happens much less if I'm holding the phone while jogging/walking. Though many times it also works well even though the phone is in my pocket or bag.

Note: In general when I use GPS, I have clear view of the sky (though of course, if the phone is in my bag, it technically can't 'see' the sky)
As long as the material of your clothes or bag contains no metallic element that could block the GPS signal then your phone should be able to receive a GPS signal fine while in your bag or pocket.

I use the HTC Desire almost daily to record GPS tracks, and generally keep it in my jacket pocket and have noticed no problems with the GPS positioning. Those problems I do have are related to travelling through built up areas or in buildings.

You should remember that GPS can be less accurate in dense urban areas as the receiver may be able to see some sky, but that patch of sky may not contain enough GPS satellites for a direct fix. The signal may also be affected by weather, particularly humidity.

Have you tried any other applications, as it could perhaps be the app that is causing the poor performance you're seeing. 

For recording running I can particularly recommend Runkeeper, I've been using it for six months now and it works really well, plus has some really good online features. For general GPS recording the My Tracks app is also pretty good. I would suggest trying a couple of different apps and comparing the results. If they are all showing gaps or jumps in the GPS track then it may well be something to do with the way you are using your phone (or the area you are in).