How can I share my clipboard between two Macs?

Is there an easy way I could send clipboard data from one Mac on the LAN to another?

You can't do this with built-in methods, of course. I've researched a bit and here are the results I could find:

Simple clipboard sharing for OS X

There are a couple of simple tools that claim to do this.

• ClipCommControl is freeware and has support for 10.4 and 10.5, 10.6 and above untested.
• Stuf is a Windows/Mac clipboard manager that also synchronizes between machines. It offers a free 30 day trial. Seems like a more recent app that is also under active development.
• ClipboardSharing is rather old, and was written at the time of OS X 10.3. However, it seems to run and install on 10.6 too. It's freeware.
• ClipboardMultiSharer is Java based, therefore works on a few platforms, but isn't that pretty. It's also free.

Here is an article from 2009 that mentions a couple clipboard managers for OS X, of which only Stuf is mentioned as having the capabilities you look for.

Synergy

If you're up to something more sophisticated, a program like Synergy, free and open source. It allows you to switch between different machines at the same time, and as a bonus, it also shares your clipboard with those.

Might be a bit over the top for just clipboard sharing, but it's something worth taking a look at if you control multiple machines at the same time.

Teleport, a virtual KVM switch, includes an option to synchronize the clipboards. It installs as a pref-pane on each computer. I use it regularly between an iMac and a Macbook.

Clipboard sharing is built into the OS X screen sharing application.