The Apple MacBook Pro security screwdriver is one of the most complicated items to buy because of the simple variety of screwdrivers as well as screwdriver heads that need to be taken into consideration. There is a different one for your MacBook as well as MacBook Pro.
Check your warranty before you buy!
Before you buy yourself a set of Apple MacBook Pro security screwdrivers, I should warn you that you need to make sure that you check the warranty on your Apple device. The things with most Apple notebooks and more so with the new unibody MacBook Pros is that they are sealed shut in a certain way and even if you are confident that you know what you are doing, opening the case by yourself is one sure way to void the warranty that the product comes with by way of the Apple Care Protection Plan.
With that out of the way, I'd like to point to a number of tasks you could do once you've got your hands on these special screwdrivers. The reason we call them special is that even though Torx screws are pretty standard on all portable computers these days, Apple is one of the few manufacturers that use the 5 head Torx screw instead of the normal 6 head Torx screw that everyone else uses. And if you're using one of the older PowerBooks then you're in for a surprise as you probably will need both, a Torx 6 as well as a Torx 5 head screw driver. On another note, even if you need to get a Torx+ screw out, you should get yourself a Torx screwdriver as they are compatible.
Which screwdriver to buy?
Since you can't really buy a single screwdriver, unless you are looking for a MacBook Pro Special Battery Access Screwdriver which is a specialized screwdriver that is used by Apple to unscrew the battery in the new unibody MacBook Pros, there is a slim shot at buying each screwdriver or head that you need even on a website like eBay. What you should do instead is buy a set of Torx or Torx+ screwdrivers from Amazon. If you already have a set of tools that you are fond of there is no point in buying full Torx or a screwdriver set. Instead, all you have to do is buy a set of small Torx screwdriver heads, the best price for which is again available on Amazon.
There are times however, when you may not know what kind of a screwdriver or screwdriver head you need to buy. This happens to me all the time especially when I have to open up a portable computer that I'm not really that familiar with. In such a situation the best place that I can refer you to is iFixit. The guides that they have on there are unparalleled when it comes to detailed instructions as well as photos and the occasional video to help you go about your project. Just select what you want to do, and you'll be presented with a list of the parts needed as well as the different sized screw driver required.