I have a better - and more secure - solution: install DD-WRT (I'm using v24-sp2 build 12533) on your router, and enable PPTP server. Then you can connect remotely to the VPN and access the router's web interface when you want to wake up one of your hosts.
After installing DD-WRT just go to Services/VPN and enable PPTP Server and give user/password. After go to Administration/WOL and configure the hosts you want to have on the wake-up list. Presto. You now have a clean and secure way to wake-up your hosts remotely.
As an added bonus, if you have an iPhone you can easily configure it to connect to the VPN. This will work out-of-box, just give the IP address or the DynDNS hostname, and then access the router's web interface on Safari. You can even create a Safari bookmark so you don't need to type the address ;)
DD-WRT forums are great and can give you any support if you need. If your router doesn't support DD-WRT, you can also buy a WRT-54G for less than 25 bucks on ebay..
Hope this helps.
