thanx to stefan k who really helped me on macscripter
http://bbs.applescript.net/viewtopic.php?pid=69988#p69988
I was able to create this applescript
if you open the script editor in the folder applescript and write this
on open these_items
tell application "Terminal"
activate
repeat with this_item in these_items
set titre to name of (info for this_item)
set question to "enter desired time range for " & name of (info for this_item)
set range to text returned of (display dialog question default answer "1-100")
set range to range as string
set this_item to quoted form of POSIX path of item 1 of these_items
set shakescript to "shake -exec " & this_item & " -cpus 2 -v -nocache -t " & range
if (count windows) is 0 then do script ""
do script shakescript in window 1
tell window 1
set title displays shell path to false
set title displays window size to false
set title displays file name to false
set title displays device name to false
set title displays custom title to true
set custom title to titre
end tell
end repeat
end tell
end open
then save it as an application, drag the application icon near the search field at the top of your finder window, wait 2 seconds until a rectangular selection appears and release it.
you'll now have an automated way to use the terminal to render time-consuming scripts without having to open shake, all you have to do is just drag and drop your shake script on the droplet icon and enter the time range in the dialog boxe
be aware that the -cpus 2 flag depends of the number of cpus you have in your mac so for a macpro it would be -cpus 4 and on a single processor machine like a g4 you can just remove this flag (core 2 duo is also -cpus 2 !!!!)
hope that will help you save time