I can't really do much about the GPS lock time, as ellweber said it probably already starts searching as soon as the empeg is turned on (i.e. when the remote amp wire becomes active).

Actually I guess I don't know about these but the Earthmate only turns itself on when the serial port is opened.

find the magic sequence to upload the current time and approximate location to the gps

I just sent it. I can contribute a patch, but it wants time in UTC. Do we want to rely on people having the right time? If so, tell me and I'll get a patch out tonight

I never got ETE working for me, but then, it might have been when gpsapp (0.7) was confused about the location of the next waypoint as relative to my position. (I was closing on it, but the estimated distance was increasing... but was almost 2x the distance of the whole trip, so I don't think it just "missed" me passing one.)

It would be hard to scroll the actual NMEA messages because by the time I update the screen, I'm working with something more like a summary of the data I got from parsing the messages.

How about an icon indicating data being received?