Texting Length?

Hey Everyone,
The iPhone is finally available in my area thanks to Bell and Telus and I have been interested in one for quite some time. I just had a general question about texting. I was wondering if the iPhone allows you to type long messages while breaking them into separate messages. What I mean is that my girlfriend has a HTC Touch and she can type and type to me and I just get maybe 2 or 3 messages so that way she doesn't have to stop and start a new message. It just breaks up her long message into so many texts. Does the iPhone do this or does it have a cut off at so many characters, in which you need to start a new message?

Thanks.

PS - probably a stupid question I know. lol