Right-click on a file or folder and select Automator -> virusscan to scan the selected Finder item for viruses.
Requires Automator (Mac OS X 10.4 or later), ClamAV (man clamdscan) and CocoaDialog (for the notification pop-up).

# get the ClamAV icon
cd ~/Desktop
curl -L -O http://freshmeat.net/redir/clamav/29355/url_tgz/clamav-0.92.tar.gz
tar -xzf clamav-0.92.tar.gz
cd clamav-0.92
sudo cp ~/Desktop/clamav-0.92/docs/html/img2.png /usr/local/bin/CocoaDialog.app/Contents/Resources/clamav.png
#sudo sips -i /usr/local/bin/CocoaDialog.app/Contents/Resources/clamav.png
sudo chown -R root:wheel /usr/local/bin/CocoaDialog.app
sudo chmod -R 0755 /usr/local/bin/CocoaDialog.app


open -a Automator


#----------------------------------------------------


Drag or add actions here to build your workflow:
Library: Finder -> Action: Get Selected Finder Items
Library: Automator -> Action: Run Shell Script
                                 - Shell: /bin/bash
                                 - Pass input: as arguments

cocoadialog="/usr/local/bin/CocoaDialog.app/Contents/MacOS/CocoaDialog"
CD_Resources="/usr/local/bin/CocoaDialog.app/Contents/Resources"

for f in "$@"; do

   /opt/local/bin/clamdscan --quiet "$f" 2>/dev/null

   return_code=$?

   if [[ $return_code -eq 0 ]]; then
 
      /usr/bin/say OK

      $cocoadialog bubble --no-timeout --x-placement center --y-placement center --background-top "00FF00" \
          --background-bottom "00FF99" --icon-file $CD_Resources/clamav.png --title "Scanned item is OK!" \
          --text "$f"

   elif [[ $return_code -eq 1 ]]; then

      /usr/bin/say "virus alert"

      $cocoadialog bubble --no-timeout --x-placement center --y-placement center --background-top "FF0000" \
          --background-bottom "FF0066" --icon-file $CD_Resources/clamav.png --title "WARNING: VIRUS ALERT!!!" \
          --text "$f"

   else

      $cocoadialog bubble --no-timeout --x-placement center --y-placement center --background-top "FFCC00" \
          --background-bottom "FFCC33" --icon-file $CD_Resources/clamav.png --title "ClamAV virus scan failed!" \
          --text "Please, check your ClamAV setup! Return code of man clamdscan: $return_code"

      exit 1

   fi

done

exit 0


#----------------------------------------------------


# save the virusscan Automator workflow as a contextual menu item
Automator -> File -> Save As Plug-in ... -> Save Plug-in As: virusscan -> Plug-in for: Finder -> Save

open ~/Library/Workflows/Applications/Finder/virusscan.workflow

# test some files in ...
open ~/Desktop/clamav-0.92/test

// description of your code here
Speed up the gnome menus by removing display delay

// insert code here..
gtk-menu-popup-delay = 0"| tee -a .gtkrc-2.0

#Now save the file in you home directory under the name .gtkrc-2.0 and restart your x session