Consumer routers will typically have port 22 firewalled for incoming trafic.
* Reverse SSH: if wget http://myserver.com/sshreverse; then ssh -R 2900:localhost:22 User@myserver.com; fi
Stick this in a file, chmod +x, then add an entry in cron to run it every hour or so. After that, you just need to create a file in your web server called "sshreverse" and you'll have an SSH tunnel to your laptop.
I would set up an icmp proxy with ssh on top of that. And there would be a few good reasons for that. 1: it bypasses a whole lot of firewalls and captive gateways. 2: few hackers would expect such a communication mechanism like that.
Of course, this solution works only if the computer isnt reformatted, as i would do if i ever got into petty theft. So one would need the computer to have an open and easy to get into account. If you use linux, have home directory encryption on and the account called "Administrator".