Scott Hanselman has a post talking about how his cousin's company ran into some difficulty recently, that Scott believes could be resolved by "net sourcing" certain functionality.
I'm not convinced "net sourcing" is the solution to his cousin's problem. I regularly hear of similar problems where companies lose access to their web site and email because their domain registration expired. Some "expert" was hired years ago to set stuff up but he is long gone, the administrative contact email is set to an address at some ISP that no longer is in business and nobody has a clue what to do. The fact that the domain registration is stored at an external service provide does not solve the problem.
Any 20-30 employee company should have a contract/retainer with an "IT guy" that is responsible for these kind of issues. Just like small companies have relationships with lawyers, accountants and auditors, they need someone to be responsible for their IT infrastructure. However, a company should make it clear to the "IT guy" that all the necessary knowledge, like the name of service providers, accounts, passwords, procedures need to be documented and stored on site so when the "IT guy" closes shop, the company can find someone else to take over.
I agree that we should focus on our technical competencies and let others focus on theirs, but choosing where the hardware should live is a bit of a red herring. It's a bit like saying you should store all your legal documents at your lawyers office.