Announcements in sidebar?

Are there any plugins that would allow for quick announcements or messages to readers to be posted in the sidebar?

For example, if I want to mention an interesting website I found, but don’t want to write an entire post about it, just hey! WordPress Forums(link) are not available!

Or, say I want to just say something like… I just bought a new car. But don’t want to post about it.

A place for small, one time only blurbs to the readership.

Any help appreciated!