About four months ago I started to get into the idea of using mind mapping to brainstorm and plan out ideas and projects. At the time, I was looking for a service that was easy to use, fast, would allow me to collaborate with others on a single mind map, and would allow me to access the maps from both work and home.
One of the best that I found was MindMeister. Unfortunately, their free service only allows for something like five mind maps on an account at one time, so I was afraid of outgrowing it.. and eventually just stopped using it.
This morning I got an email from them reminding me that I haven't logged in for about four months and offering me their "sleeper package" – a license code good for 2 free months of their paid features, and 5 additional 2-month licenses for me to give to friends.
I'll give them to any of you, if you want them. The first 5 people to leave a comment asking for a promo code will get them.
(I still use mind mapping occasionally, but my setup is a bit different. I use the open source program Freemind, and then use the DropBox service to synchronize the map files (along with a bunch of other stuff) between my laptop and my work PC.)