So why does Apple's Might Mouse suck so bad? I swear, once a week the scroll ball will stop working...well, half-stop working - I can scroll up pages, but not down. And it'll do this for a few hours and then decide that it'll start working again. Absolutely maddening!
They're good at the big picture - but little things like this, and the iPod batteries really frustrate me. How can they be so good, yet create these little design flaws and not fix them?

because, you know, apple products, just work...

I just use the two button functionality and have never taken it further. I completely forget about the side buttons and the tiny scroll ball.

I just use the space bar (and shift space bar) to navigate up and down web pages. Or page up and page down keys in documents.

I had the exact same problem. Scroll down worked intermittently, then stopped altogether. I swapped it for the two-button/middle wheel Dell mouse I'd previously used with my PC and ... bingo! Problem solved. Better yet, two-button functionality on the Mac eliminates the need to use two hands for some actions. OS X will recognize a USB non-Apple two-button mouse and assign functions to the right button accordingly. Much better IMHO than the one-button default.

If you can't get a two-button mouse soon, you might try the voice-command function. "Move page up" and "move page down" work well.

OMG! I just started playing around with voice command - this is too funny!
My computer now sounds like Soundwave!

Yeah, it's a crack up but it can become annoying too. If you want, you can turn off the talkback function and replace it with an assigned sound or just silence. Once you do the training thing a few times, it becomes more sensitive to how you pronounce the commands. It's surprising how many there are that aren't listed. Some software can be operated entirely by voice commands.

Beware the "tell me a joke" command. It tells incredibly stupid knock-knock jokes.

90% of the time the ball stops working from oils and junk from your finger tips...

-Clean the ball
Wipe any dirt or crud off your finger. Then, while holding the scroll ball still with your other thumb, wipe the scroll ball with your finger. This should get it to start working, even if just for a moment.

- Blow into the mouse
Be careful not to spit on your mouse when doing this. blow right on top of the scroll ball. Listen for the 'blowing though a straw' sound. Do this until it starts working again...

if that doesn't work take it the Genius Bar and they may just swap it...

jawkdna are you referring to conventional trackball mice or the Apple Mighty Mouse specifically? The ball is so tiny that even one thumb would get in the way, and although I haven't tried it, I'm not sure the unit can be opened as with trackball mice.
I dunno ... given the lame design flaw of the extremely short cord, I'm inclined to think that it's better to just buy a better mouse unless you want to try the wireless version. I could never get used to those side buttons anyway. Remind me of pinball flippers.

I have had a lot of problems with my wireless mighty mouse. It used to suddenly go into slow motion about once a day. Since I upgraded to Leopard, I seem to loose bluetooth connectivity altogether with no real warning.

The scroll ball not scrolling down is a common problem. Usually it's a bit of crap flopping around in there causing the trouble. The best thing to do is to hold the mouse upside down and push really hard on it and roll it around.

yes that is what I meant!

Sorry I copied and pasted from the wrong section of an article in my post above...

I've tried all the suggested methods to get it working. And while it does start working again, it's not as easy as these methods suggest - it takes anywhere from 30 minutes to 4 hours.
I think I'm just gonna have my boss buy me a new mouse. The mouse pictured above sucks, and it can not be opened to be cleaned...actually, that's the only reason it sucks, otherwise it's actually pretty nice. Just has one serious design flaw.