free hosting is either very limited, or very gimmicky, and if you care about your friend you won't screw him over by moving his business to free hosting, and you should tell him (in terms easy to understand) that free hosting = bad business. Besides, he's got his own server, so he should be the 1st one interested in fully owning his own business, thus transferring it to his own damn server.
I've compiled a list of free hosting providers about an year ago, you can probably (still) find it if you search for free hosting using my BHW username... or was it cheap hosting ?!? I don't remember... but either way, I think I may still have that list somewhere on my computer, if you really really REALLY want it so badly I can search for it and post it here, so let me know. But that list is pretty old (probably 1 year or older), so I'm not sure how many of those providers are still offering free hosting, or how many of them are still in business. But in all honesty, you can now get reliable hosting for like $5-6 per year if you shop around for good deals, so you should urge your friend to stop being such a little bitch and get his own hosting if his own server is too full or something