Or do you mean addon domains? If so IM sure you can find that arround here. You should try out the offers section, and if you don see anything 5 addons ask them by chatting or calling them to see what they can do for you.
Hi miseria. From what you say, it sounds like you mean sub-domains (like: first.mydomain.com + second.mydomain.com etc.). I am sure most every host will let you have most any number of those!
If you want several Domains on one account, it's a bit different.
Some hosts let you, some don't.
For example, Micfo will let you have a couple of sites with different domains on one account, at no extra charge. Lunarpages allows it, but charges a little bit extra. And so on....