HPShortcutManager is bogging my CPU.

It's HP scanner software. To get rid of it, you'd have to use the uninstallation tool provided, or otherwise follow the developer's instructions. You might have to download it again from HP and even reinstall it in order to remove it.

In the Finder, select Go > Go to Folder... from the menu bar and enter "/var/db/receipts" (without the quotes) in the text box that opens. From the "receipts" folder, delete anything with "HP" or "HewlettPackard" in the name. You'll need to authenticate as administrator to do this. Then open the folder /Library/Receipts and do the same thing. That may stop the prompts to update the software. If not, just check the box to ignore it in the Software Update dialog.

You can also go into library\application support\hewlett-packard\hp scanjet scanner and delete the app 'hpshortcutmanagerstartup.app'. But you need to go into activity manager and force quit the process first. You also need to enter your root password. And *POOF* hpshortcutmanager can be stopped and it won't start back up.

Apparently it's a very sloppy written utility that repeatedly scans the USB bus for the scanner looking for the shortcut buttons. There is a way to go into the HP scanner application and turn off the shortcut buttons but it does not stop the shortcutmanager from starting in most cases. This kils the part that allows it to continuously restart. I don't know if the app starts up if you need to scan as my scanner is unavailable a the moment.

HP seems to be quite characteristically silent on why, and how to fix, this problem. Until HP does fix this issue, this is the best workaround I've found.

This still seems to be a problem two years later on Mavericks. Shame that every time I want to scan something I have to reinstall the HP software and then uninstall it again!

This program starts automatically; stop that and your problems will be solved. Go to system preferences, accounts, the log in panel, unlock with your root password, select hpshortcutmanager, delete it with the - button, relock with your root password, restart your Mac and voila.

realgonzoid's solution did it. Forget uninstalling and reinstalling every time. I just took the file elsewhere (not to trash) where Mac OS X won't start it and if needed, throw it back and let it do its thing later.