So long as you didn't do a Secure Empty trash then there's a chance. But it's not easy in OSX. You can try Norton Utilities using Unerase. You can try
Data Rescue X. With Disk Utility you can also use Restore. But with all of these options you need a different HDD or partition to recover the files to.
Others:
search results link &
Shareware for OSX link &
mac shareware 2 link
About Norton unerase here:
http://www.circa.ufl.edu/handouts/mi.../norton.html#4 http://codetek.trakhelp.com/bin/answ...er=113&topic=1
If I'm deleting incomplete files, I prefer to do it outside of LW whilst LW is closed; ie: go to incomplete folder & delete those I don't want anymore. Then open LW & delete the same ones from the download list window.