With Analytics and Webmaster Tools you could do two things, have seperate accounts for seperate business/companies you have set up, hopefully which all have different details, including IP's you access them from. Otherwise just use other stats packages, reinvigorate.net is one i have been using for a while, not too bad at all.
Shags, I have used SEOHosting.com for a feature like you suggest, yes it does work to some extent, its good to go even further, and have hosting accounts from multiple web hosting companies, thats to really spread out your sites.