We recently featured a way to launch applications and perform actions on another computer with Dropbox and AutoHotkey, but it was a bit complicated. Here's an updated version that just requires a quick keyboard shortcut and a bit of AutoHotkey scripting knowledge.
The old method required editing a script, saving it and then going back into it and deleting the script afterwards. Now, with just a bit of setup, you can perform any action that can be scripted in AutoHotkey with just a keyboard shortcut. You'll need Dropbox and AutoHotkey installed on both computers for this method.
To set it up, go to your remote computer (the one on which you want the actions to be performed) download the remoteAction script and put it in your Dropbox folder. You'll also want to make a shortcut to it (by right clicking on it and hitting Create Shortcut) and dragging that shortcut to your startup folder, so it starts up with your computer.
Afterwards, go to your local computer (from which you'll be performing the actions) and download the makeDummy script. Right click on it and hit Edit Script. Make sure the path to your Dropbox folder at the bottom of the script is correct (it wasn't for me). Then save the script and drag it into your startup folder. Then, either restart your computer or double-click on it to start it up.
Now you can just hit Shift+Windows+A at any point in time, and a text box will come up. You can type in any AutoHotkey action and hit OK. Your remote computer will then perform that action. César, the author of the scripts, points to a few useful examples on his blog post for actions you can perform:
MsgBox, mum, call me right away, I forgot our home number again!
will send an alert to whomever is using your remote computer at the moment,
will run a batch file in your Dropbox folder,
will shut down the computer, and
Run, C:Program FilesLogMeInx86LogMeIn.exe
will run an application; in this case, LogMeIn.
You can run literally anything that can be scripted in AutoHotkey, so check out their documentation for more ideas. And, of course, share your own ideas in the comments.