Look into Wake-on-LAN. I don't know, though, if your Actiontec router will let you remotely log into it (the router) and send a Wake-on-LAN packet to your computer. If not, you might consider getting a router that can run DD-WRT or Tomato firmware, which does support this.
Alternatively, there do exist power strips that can be remote-controlled over the network, but they tend to be a more expensive solution.
Update: This link may be helpful.