I've seen both - does it matter as long as you stick to the same one all the way through?

Cheers.

Depends what its grammatical function is.

"The house is in between Rochester and Canterbury."

"In between rainy spells, the sun shone."

but if it's being an adjective:

"It was one of those in-between days, neither rainy nor sunny."

"In-between designs never work: you need to decide properly what kind of garden you really want."

Emma

Blimey, i never knew that - thanks very much, Emma.