One of the key features missing from Mac OS X is the ability to cut and paste files in the Finder; you can only copy and paste. With two handy Automator Services, though, you can do either through simple keyboard shortcuts.
Unfortunately, it doesn't work exactly as the cut and paste functionality in Windows, but it's about as close as we could get. The main difference (on the surface, at least) is that you'll need to assign a different keyboard shortcut to pasting cut items than you use for copied items. Here's how to set it up.
First, download this zip file containing two Automator Services (Cut File and Paste File) and extract them to your ~/Library/Services/ folder (if it doesn't exist, you can create it). Then, open up a Terminal and type in this command:
Next, go into System Preferences, hit Keyboard, and go to the Keyboard Shortcuts tab. Hit the plus button to add a new shortcut. Choose Finder for the application, "Cut File" (without quotes) for the menu item and anything you want for the shortcut—I use Command+Shift+x, which is similar to the traditional shortcut for Cut. Then, hit the plus button again and do the same, but with "Paste File" (no quotes) as the menu item and anything you want as the shortcut (I use Command+Shift+V).
Now, whenever you want to cut and paste a file (or multiple files) from Finder, just select them, hit Command+Shift+X, go to the folder where you want to paste them, and hit Command+Shift+V. The original file won't be trashed until you paste it, so if you forget to paste it, it won't go away. Unfortunately, this only works for files at the moment and not folders.
Note that I just wrote this today, so be sure you're backed up when you try using it, because you never know what small errors might have creeped in. And of course, if you notice any errors in my code, let me know in the comments!
Update: Unfortunately, there's a problem with the paste script that makes it only usable on my computer. For now, if you want to use it, you can open up Paste File in Automator, remove the .cuttemp folder from the first action, and replace it with your own (you'll have to show hidden files and drag it from your desktop into the first action's box). I'll update the post when I fix the problem.
Update 2: Everything should be working now. The only snag you might hit is if your primary hard drive is not named "Macintosh HD". I'll work on it and see if I can't find another way, but most people should be OK. Alternatively, you can open up the Paste script in automator and replace the cuttemp folder in the "Get Specified Finder Items" action with your own.