A couple of months ago, Heap CRM added find dialog boxes to lists of Google Docs or available prospects. This has now been expanded to when you are first creating a prospect and want to connect it to an existing person. Just go to one of the prospect list pages and click the create button:
Select "- find -" from the drop down:
And type in your search phrase.
Additionally, you can now see the related prospects or active prospects directly from any list of people. Just click on the indicator and a bubble will pop-up: