Drag and drop items as attachment in Entourage
For most Macintosh applications that accept drag and drop, you can drag and drop files to their Dock icon. So your "flow" might be:


Open the finder window with the file you want to send
Drag it to your dock
Drop it on the Entourage icon
Entourage will launch and should give you a new message, with that file attached


Hope this helps.