How can I see all of the grabs I've taken so far?

To see a list of all of your recently uploaded grabs, click on the Menubar / System tray TinyGrab icon and a dropdown / popup menu will appear with a list of the URLs to your most recently uploaded grabs. Click on these URLs to perform an action which can be defined in the app's preferences.

TinyGrab for iPhone users can see their recently uploaded grabs by clicking the "Recents" button on the bottom menu, in the TinyGrab for iPhone app.

You can also see every single grab you've ever uploaded, name it, describe it, search for it through the TinyGrab online control panel. Visit http://tinygrab.com/panel.