You'll get jacked for sure with this in mexico, but it's pretty much one of the coolest things ever: http://www.internetanywhere.us/pages/883501/index.htm
If I remember right, then you could look at a paper/call broker for the O,H,L,C and manually imput it. Then while on the road you could call the broker for updates and to make orders. This will be more swing trading, but gives time to enjoy your vacation. I hope this helps.
Keep in mind that in really rural Mexico, it is not all that unlikely that you will NOT be able to just call your broker in some places. At times, the phones just don't work. Have you considered really taking a vacation? The market will still be here, and I'll bet your girlfriend would enjoy it! Good Trading, Jessie