Hello, I'm looking for other options for my hosting biz.... any recommendations? Provide VOIP service?

What is your current target market?

Remember, you don't want to provide too many services, many times companies try to expand too much and lose focus in many areas. If you find yourself busy with what you have now, then either find a partner or hire someone else to manage new things.

Anky is right, check whether it is manageable or not, you can add a sitebuilder/ referral program instead.