admbws's Journal: Bonding two VPN connections?

I posted a similar story a while back to Ask Slashdot, but it's pretty dull so it got rejected. But I'll post it here anyway. I've changed it heavily since I can't remember exactly what I wrote originally, and I've made it more specific to me (this is my journal after all).

I use ISDN, and my current internet connection utilises just one of the two availiable channels, with the other free for phone, fax etc. I use a flat-rate (unmetered) ISP, and like all inexpensive flat-rate ISP's, they only support one of the channels, bonding channels for a speed of 128k is not possible.

I could easily obtain a second account with a second ISP, and call both at the same time. However, this of course only yields two 64k connections, which is not as helpful as the one 128k connection.

The question is, is it not possible to create two VPN connections, one via each connection, to a colocated server (that I happen to have access to), and bond them from there, thus giving a maximum theoretical speed of 128k? And if so, how could it be done? All systems are running Linux, and before you suggest, broadband is not availiable :-)