The Linux kernel has a little known function in it called TEQL.   When you 
compile your kernel, look in the advanced routing and QOS sections for this 
function. It allows you to take two physical devices and use them as one 
WITHOUT any other support by any other party. So your ISP doesn't have to 
support it.    The trade off?  This only balances outbound traffic. Inbound 
traffic, because of the nature of IP, will go to the physical interface that 
it was sent from, so this is no real added benefit when it comes to things 
like telnet sessions.     You will need the iproute2 package and a lot of 
patience as docs really don't exist for this function. Look in the kernel 
sources under net/sched/sch_teql.c  for some idea of how to use TEQL. When 
the game is all said and done, you will have a device called teql0 that you 
can send all of your internet traffic to and have it load balanced across the 
two interfaces. I have had great luck using this for things like web 
browsing, but remember, it will ONLY load balance outbound traffic. 

Good luck.

Jason
www.cyborgworkshop.com
...and the geek shall inherit the earth...