Q: What is the url of the website to see someone's track?
A: Go to aprs.fi and enter the call sign of the tracker
Q: Is there any ability to limit who can see your track?
A: No, but you can use a "tactical" call sign and a misleading Icon ( you could make your aircraft a sailboat for instance) as long as you enter your actual FCC call sign in the comment field to keep the transmission legal.
Q:Is there any historical data and is it searchable/downloadable etc.?
A: The Raw data is archived in a number of areas but don't count on anything but recent info.
Q: Is there coverage in remote areas / mountain regions?
A: Maybe. At Altitude, you might hit digipeaters from hundreds of miles away, in Canyons, not so much.
Q: Canada and the Caribbean?
A: Canada uses our frequency (144.390) and has good coverage over most of the Country. I am not sure how to answer your question about the Caribbean. Other Countries have different frequencies, or no APRS at all.
Q:SPOT has the ability to send basic "I'm OK messages". Does this have anything like that? I would love to be able to send SMS messages while I am flying.
A: This unit (The MT-RTG) is a "dumb" tracker, but you can send E-mail via the APRS Network if you are in range of a digipeater, which will port your message over to an "I-Gate" or internet gateway. You need a transceiver to do this. We sell a product called the MT-TT4 to do this, and OpenTrac has a similar product ( without a built in radio) to do this as well. Of course, with either of these, you can also see the position of other APRS stations on your display GPS.
Allen
VHS
www.byonics.com