[mitchilla]

This takes a little bit more effort than a full-system VPN, but it has some major advantages. Although many paid VPNs are quite fast, they're never as fast as your own internet connection. If you use a VPN that can be configured per application, you can enable it just for RuneScape-related applications, while keeping your other applications on your own (faster) network. This does not decrease your anonymity for RuneScape-related activities, but any other activities can still be spied upon by a government or your ISP. This is definitely an option you should consider.

Ivacy (as mentioned above) also provides this functionality.

Ivacy: Best VPN Service Stream Fast, Stay Anonymous & Surf Safely
HideMyAss: VPN Service for Windows, Mac, iPhone & Android | Hide My Ass!

Just a heads up, Ivacy will not launch the offical OSRS client. Even if you launch Runemate through Ivacy, Runemate will launch the client normally and will run via your own unencrypted connection and not your VPN.