Trello – Bookmarking in Trello

The Trello guide is a little bit out of date. If you are the owner of a board, you can rename it like so:

1. Click the board title (or the "Board Menu" button)
2. Click "Profile"
3. Click the name of the board (at the top)
4. Type in the new name
5. Click Save

In the lines of the solution by @bryan-larsen, I've created @welcomebot, a Trello bot that automates the process of getting people into a board.

In his own words:

I'm a bot designed to make Trello boards open for anyone to enter.

If you have a board where you want to let anyone enter, to comment and see and all that, just create a card, name it in any way you want (it can be something like "Welcome to this board, please comment here to enter!") and add me to that card.

Every Trello user who leaves a comment in that card will be automatically addded as a "normal" member to the board.

There's a test board where you can see the feature in action.