I find that several times a day I save a file then compose a new email, click the add attachment button, and try to find the file.
Does anyone know of an app or applescript to make it easier to simply save and email?
The app you want is called Mail. Seriously, what you need to do is save your file in whatever application you are using, then click the proxy icon (the little document icon found in the title bar of the window next to the document name) and drag it onto the Dock icon for Mail. This will create a new mail message with the file you just saved as an attachment.
No script or other app needed; awesomely, it's a native feature of OS X.