Correct, the i7210 does not have it's own GPS.
The Holux GPSlim 236 is just a small GPS receiver (about the size of a medium-sized numeric pager) that can communicate with the PC over bluetooth. Read about it in this review:
http://www.pocketgpsworld.com/gr236.phpYou can buy one off of ebay for $65-100.
It is very easy to setup. On the i7210, there's a bluetooth manager called Blue Soleil. It sets up virtual serial ports and personal area network addresses for bluetooth devices. If you make sure the bluetooth radio is on on the i7210 and turn on the Holux GPS receiver, then Blue Soleil will automatically detect it as a new device (See capture):
If you right click it, you can connect to it, then BlueSoleil will assign a virtual COM port to that device. In my case it picked COM4.
Next you right click and select "Pair." You will be prompted to enter a security code. The default is 0000 for this device new. From that point on, whenever any app opens COM4, BlueSoleil initiates a connection with the GPS receiver and it looks as if it's connected over a normal serial port.
Therefore, any app that can speak to a generic GPS that talks NMEA version 2.3 protocol can use this receiver.
Why did I pick this receiver? Primarily because it has the SiRF III chipset in it which is well know for fast cold start satellite acquisition times and good tracking capabilities in cover such as forest and urban areas with hi-rise buildings. Other niceties are,
- low cost
- communicates with PC without wires
- rechargeable non-proprietary battery that lasts ~8-10 hours and can be charged directy from USB port with an A-to-mini-B cable
So far I've been very happy with it.