Shareaza

I would assume Shareaza has to create a physical file somewhere on my harddrive of video files i have previewed, but for the life of me i cant find where, can someone please point me to the folder where these files are located.

They are located within your incompletes directory. Note however that Shareaza does clear them up once they are not needed anymore. If you would like to keep them permanently just open your incomplete directory, then hit preview within Shareaza and copy the file from the incompletes directory once Shareaza has completed its creation.