Using - in titles?

Does anyone know if using a hyphen in an item's title impacts on search results?

Can't say I have any real evidence one way or the other.

One reason I don't use them (or any other) "special" characters unless absolutely necessary is because I've read on other boards the opinion that Google doesn't like them and might reject titles that include them.

I've no concrete evidence to support that idea either, but better safe than sorry??