first, youre gonna have to use Mail, if you dont use it already.
then use this Applescript (open Applescript Editor in Utilities)
Code:
set newline to ASCII character 10
tell application "System Events" to set iCalIsRunning to (name of processes) contains "Mail"
set finalText to ""
if iCalIsRunning then
tell application id "com.apple.mail"
set unreadCount to (get unread count of inbox)
if unreadCount > 0 then
set theMessages to (messages of inbox whose read status is false)
repeat with i from 1 to number of items in theMessages
set thisMessage to item i of theMessages
set fromMsg to (sender of thisMessage as string)
set subjMsg to (subject of thisMessage as string)
set dateRec to (date received of thisMessage as string)
if subjMsg = "" then
set subjMsg to newline & " No Subject"
else
set subjMsg to newline & " " & subjMsg
end if
set finalText to (finalText & fromMsg & " - " & dateRec & subjMsg & newline)
end repeat
end if
end tell
end if
finalText
finally this command in geektool
Code:
osascript YOUR/PATH/TO/FILE.scpt
you can change the aspect of the output in the applescript.
have fun!