My Thinkpad's power connection started getting flaky, so I made a magnetic connector that works just like Apple's MagSafe connectors. It's effective, cool-looking, and breaks away cleanly when kicked. I used common materials that I had around or could find at my local hardware store, so you should be able to duplicate my efforts.
These directions should work for any power connector that has the same basic design, if you make adaptations for differing sizes. See the second and third pictures in this step for a "before" portrait and a little bit of terminology.
This modification isn't destructive in any way, so it should be possible to restore your laptop to its original condition just by removing the pieces you've glued on. You can't use an unmodified power adapter once you've modded your laptop, but fortunately it's pretty easy to make the plug part, so you can make two or more spares.
Remove the battery before working on your laptop, and unplug the power cord.
Step 1: Materials
In addition to what you see here, you need:
a soldering iron
You will notice in most of the following instructions that I only used two magnets. This is because during my initial build, I thought that two would be sufficient, and it was only when the whole thing was built and photographed that I discovered that they were not. Rather than start over, I simply used my Dremel to insert another two magnets, and the final design you see on the first page was born.
Depending on how many materials you already have, this should cost less than $30 for the whole project.