Easy answer for this one: There is a Mac equivalent to ctrl-alt-delete. Move out of your stuck application by clicking on the desktop or another program, then press opt-cmd-esc. Alternately, you can go to the Apple menu and select Force Quit. This brings up a list of running programs to choose from to force quit. The stuck one is often listed in red lettering. An easier way is to control-click (right-click) on the program's icon in the Dock and select Force Quit from the pop up menu.

A third way to bring down that stubborn program is to open Activity Viewer in the Utilities folder and select the stuck program from the list of running programs, then hit the Quit Process button. Sometimes it takes all three ways for me.

Is there a reason that my Mac gets mad at me when I just unplug a USB device? My PCs are fine with it...

The warning should only come up with removable drives like iPods, thumb drives or external hard drives. The Mac essentially adds some safety precautions for these drives so you don't disconnect while something important is going on. The Mac also does a little "house cleaning" before releasing the drive.

The correct way of removing these devices is to "eject" them. You have a few choices as to how to do this. The quickest way I use is to click on the little triangle eject symbol next to the device's name in the Finder sidebar. I usually have a Finder window open, so it's a one click thing for me.

The totally unintuitive option is to drag the drive's icon on the desktop to the Trash. You'll notice when you do that, the Trash icon turns into an eject symbol. Very kludgey, Apple. Two more ways is select the drive and then hit cmd-E or Eject from the Finder's File menu. And last but not least, control-click (right-click) on the icon on the desktop and select "Eject" from the pop up menu. There you have it: 5 ways to eject a drive.

I have to admit that although there are horror stories on the Internet about skipping this process, I've never had any damage from the uncountable times I've inadvertently pulled out a drive without ejecting it.

iChat can use EITHER a .Mac account or an AIM account or a Jabber account. AIM stands for AOL Instant Messenger. AOL will provide you with a free screen name by going here to register for one. Once you have an AIM screen name and password, open iChat, and select Preferences from the iChat menu. Click on Accounts then the little plus sign in the lower left. Under Account Type, change it from .Mac Account to AIM Account. Then fill in the rest of the info and you should be good to go.

Don't forget you can do video or audio conferencing with iChat as well if your counterpart(s) has a Mac too.