The Pacsafe backpack protectors/security web is the most secure option when you're on the road and it is the only way to lock most top-loading backpacks:
http://www.travelgear.com.au/mm5/mer...y_Code=PACSAFE
If you're more concerned with ensuring that baggage handlers don't mess with your luggage you may want to look at tamper seals, like the Tampertell:
http://www.travelgear.com.au/mm5/mer...Code=SECTAMPER
The glad wrapping process is something that is done by companies at the airport and it is not available at every airport.
More travel security products:
http://www.travelgear.com.au/mm5/mer...egory_Code=SEC