Suppose I have the file
Can I directly transfer it to Google Docs without downloading to the computer first?
Open the dialog for uploads and copy+paste the address in the 'file-name' box, making sure to INCLUDE the http:// (or https://)
N.B. This will upload the zip, and not extract it. If you want the zip extracted first then you will need to download it to your pc and extract it before re-uploading all the files (AFAIK)
I use a Chrome extension called Cloud Save which allows for downloading directly to a number of cloud services, including Google Docs.