Since your router is Linux, I assume it must also have an SSH server on it. So here's what I do when I need a quick-and-dirty (but secure) tunnel to browse the web with:
First, I log in to my VPS via SSH, like this:
ssh -N -D 1080 my-vps.example.com
Next, I fire up my FireFox web browser and configure it to use the SOCKS proxy server that my SSH connection has just created at
localhost:1080. Also, in the FireFox
about:config page, I double-check that
network.proxy.socks_remote_dns is set to
true, so that my DNS queries are sent over the tunnel as well. (Very important!)
Finally, as a sanity-check that my browser requests really are going out through my VPS, I browse to whatismyip.com, and verify that the IP address it reports matches the static IP address of my VPS.
When I'm done browsing, I close the tunnel by terminating the SSH connection. It works pretty well for occasional use, and it should be as secure as SSH.