Absolutely. You do this by creating a folder action, which means attaching an applescript to a folder in Finder, that gets run whenever a new document comes in.
- Install folder actions using the Help->Install add-ons menu in DT
- Right-click on your folder in Finder, and choose “Folder Actions Setup…” (may be in the Services submenu)
- in the dialog that pops up, choose one of the DEVONthink scripts (i.e. “DEVONthink - Import, OCR & Delete.scpt”) and press “Attach”
- Drag and drop your files in (or have them automatically sent in via scanner)