What are ways of practicing blindfold chess? Is there a way to practice blindfold chess on the computer?

For example, are there any programs online which give only a transcript of the moves played, and allow you to type in your next move, rather than showing a board?
Not strictly on a computer in your sense I assume, and, depending on how good you are, potentially not challenging enough: A friend of mine did this with an old second hand chess computer. The kind that comes with a board and pieces. The board is touch sensitive to register your moves and has LEDs to indicate computer moves. He played without the pieces. 

The advantage: Many of these take batteries and allow you to play anywhere.