Link aggregation with DSL and Ethernet, and different ISP's?

Solution 1:

You almost certainly can't combine the two lines in the way you probably want, where a request goes out one pipe/ISP and comes back in the other. The issue is your current ISP would need to be able to route your new IP block and that is highly unlikely.

What will probably be a better solution is to break requests out into services on different pipes or segment traffic based on IP. So you may send all web traffic to one pipe and all ftp traffic to another. That is actually not too hard to do with a CISCO router or any number of open source firewalls like Shorewall.