I've already mentioned this somewhere else on the site but I thought I might as well put it here as it was pretty useful and worked reliably with no issues so far whilst using it first hand.

I found this thing particularly useful for hooking multiple audio interfaces to a single computer system/DAW for use in a single instance of a loaded audio application like Ableton. Its basically an ASIO driver that allows you get lots of different ASIO capable devices working at the same time via this single universal driver. Something like Ableton would normally only let you use one ASIO capable audio interface at a time however this driver helps you get round that limitation. You'll have to fiddle around with the settings a bit if you're using different devices with different latency thresholds in order to get them all synced up which you can do from a single control panel lauched from the system tray. After which the additional ASIO channels from any additional ASIO capable audio interface(s) should just show up in Ableton as additional assignable audio channels as if it was one big audio device whether they be for input or output. There's also a rewire feature too if you should need it. Windows 7 64-bit users needn't worry as its fully supported with the most recent update release, plus it seems to work just fine under my Windows 7 64-bit setup so far.

You can get it here for the cost you paid for your connection and the equipment your using to access it.