I use a free number, supplied as part of my ntl account. But my website is still on freeserve, and I can't access it for editing purposes except through freeserve.
I've decided for the time being to leave it as it is - it's just a few local rate phone calls a week, and loading modifications and additions using WS_FTP is very fast. It's only a few pennies. And I quite like the feeling that all my eggs aren't in the same basket.
If I ever do decide to change where I keep my website (or if freeserve wants to start charging or somethig like that), I have a proxy URL via bigfoot, so can it won't mean hassles about letting people know the URL has changed, because it won't need to.