Off-screen windows
How are you supposed to click the green button if the window is off-screen?
I have this problem too. The top of the window, including the menu bar is completely off-screen, so there's no way to click on an active part of the window to drag it back on-screen.
I've tried all the features of Exposé, but can't find any that let you actively move a minimized window (it's just an image of the window, not the window itself). Bringing the window to the front doesn't help, you still can't click on a draggable edge.
It used to be possible to drag from other parts of the window in old versions of Mac OS. Why they got rid of it in OS X is beyond me (I remember thinking "Oh, oh," the first time I noticed it had changed) and I can't find an option in Finder to tile windows either (which would solve the problem).
I don't have Snow Leopard, I have Leopard, so I can't use one of the nifty apps out there that has these capabilities and I'm not going to pay $20 for something that lets me drag one window, one time, back onto the visible screen. The OS should let you do that. I vote to have at least two edges (instead of only the top edge) draggable so this problem doesn't happen.
Is there a tile function somewhere that's hidden?
I'm going to try to use the detect screens to see if I can shuffle things by brute force, and you might try that too, but it shouldn't be necessary to resort to such crass solutions. I love OS X, but the limited window tiling and dragging features need to be fixed.
Okay, here's an addendum:
I tried detect displays (didn't help), and setting different resolutions on both monitors. At first it didn't work, no matter what I selected the top of the window was still off the top of the display, but eventually, after trying about 5 different monitor resolutions, the OS moved the window down to where I could grab it. Not an elegant solution but it might help if you're stuck.