How accurate is the GPS in my Mobile Phone? I was wondering how accurate is the GPS is in my HTC Desire Android compared to a dedicated hand held GPS unit or in car satnav?

The reason I ask is that I have read articles complaining that the iPhone's GPS is not very accurate and wondered if it applied to all mobiles.
I have an HTC Kaiser (AT&amp;T Tilt) that I had Google Maps installed on.  Google maps gave me the number of satellites that it could see in parentheses at all times.  When I used my phone's internal GPS, I would get about 4 satellites, when I would use an external Bluetooth GPS, I would get about 12 satellites.  When I use my TomTom, I get about 7.  The number of satellites is the biggest deal for getting good location; the more the better.  I never tried an external GPS antenna on my HTC Kaiser to see if it was just the antenna that was the issue or if it was something else.

The program called "GPS Status" available from Google Play Store, will show you how accurate your GPS is at any given time. The number of bins with green bars in them is the number of satellites that your phone can "hear/see" at any given time and then it also gives you the accuracy in meters on the display.