Ianal, but iirc the DPA applies only to personal information. You're allowed limited amounts of info for the management of your accounts etc, but anything more than that you will need to register as a data controller. That counts whether you create, store or otherwise process data.
If you're just hosting small static sites with a contact page, then no, I don't think you need to register as a data controller. However, if your server space is storing personal information on there, especially if it's personal information about the users of the site, then you'd best look into it further.
Take a look at
www.ico.gov.uk - they've got good guides on there, but if that doesn't answer your questions, it's probably best to go find a solicitor who deals with DPA enquiries and ask them for advice.