If I were making the site for multitasked.com, I would set it up as either one of two ideas.
1) A software sales and review site, focusing specifically on organization, business management type software. Software that can be used for increasing productivity would be good as well, and maybe incorporate similar category PDA software. You could sell advertising space, work with AdSense ads, or profit by using affiliate links for all the software you feature/review.
2) A site that teaches time-management and organization. Business professionals have such demanding schedules, and multitasking is very important. There are a great deal of brick and mortar companies that sell organization services, and you could emulate that in online form. Obviously, this is the much more difficult of the two because it would require a good deal of research or hiring very knowledgable people in the industry. But I do think it's a great idea.
Anyway, hope one of them at least gives you a little direction.
Good luck with the site
PS. Value for the domain alone, I'd say low $XX reseller and high $XX end-user because it's not a common usage like "multitasking" and considerable work/advertisement would need to be done to make the site return a nice profit.