This is similar to what you are looking for - InfoTip - http://www.na.rim.or.jp/~norio/index-e.shtml
- You need to add the info in a tab under properties though and not just as a text file in the folder.
The page also has another utility, ZipTip - shows the contents of zip files in a tooltip.
You should check these out even they are not the exact same utility.
Great little timesavers... have been using these for about 7 years with no issues (even though the site says alpha)
-Edited to make sense... re-read what I wrote and realized that it was incoherent... well is 4:00am and I havent slept-