The offline mobile interface for Heap CRM now has a specialized version for tablets (most notably the iPad). This is the very same software that you can run offline on your iPhone, Android device or Palm Pre; it just detects the larger display and uses the space more efficiently. The menu on the left is always kept on the screen, even as you scroll down the page.
But, because of the way this implemented, this interface is already available for future tablets. Any tablet running the iPhone OS, Android or WebOS (Palm) will just work.
The main Heap CRM interface also works on the iPad, but if you are on a shaky to nonexistent connection, the offline mobile interface is the way to go.