Here is an applescript droplet for putting text files into the inbox.

Any .txt file(s) which are dropped onto its icon will be treated as follows:

1. The first line will be used as the name of the task
2. all subsequent lines will be copied into the note of the task

Any files with an extension other than .txt will be ignored.

Could be extended, applescript interface permitting, to allow for dropping any file into the inbox, with the file name being used for the task name, and the file itself becoming an attachment. As far as I can tell the applescript library does not yet allow this ...