I found a very interesting article
HTML Code: 
, that gives a real-world example of a way for a user to access context-sensitive data (in this case, while in a summary worksheet, accessing details in a given record in another spreadsheet).

This is a bit above my level, but I am willing to start researching this and trying to modify their code examples for my application, as I think it will add some real power to the spreadsheet, versus the otherwise clunky VBA and hyperlinks I currently have in mind. BUT, it's my understanding that smart tags are disabled in 2010, so will I even be able to make something like this work?