Copy and Paste Extreme
I just finished an update to my new software Copy and Paste Extreme.
This software lets you copy something to your clipboard on one Macintosh, and paste it on another Macintosh. This is great if you run more than one Mac, which I do at work. I can copy something to my clipboard on one Mac where I just run my development tools, and then paste it into an email message on another Mac which is the only Mac running my Mail program.
Since I started using it, I can't imagine not having it.