I'm a SlickEdit person at my job. But, since everything is packaged so nicely for Android into Eclipse I figured I might as well try to go native. Eclipse has got some really cool features - auto-completion, live updates, etc. Couldn't figure out how to open and VIEW multiple source files at once until now. It's so simple.
Open up both files in Eclipse. You should have a couple of tabbed items. Normally, you just click on either/or and that's what you see. To give one of the tabs its own window, simply left-click and drag it down. You'll see your icon transition to an arrow. When you let go when this happens, that file will open up in its own window. You now have multiple windows going. You can configure a side by side or above/below configuration. Woot. Not as quick to configure as my Brief emulation under SlickEdit, but it works.
Now.... where's my second monitor to really take advantage of this? :)