yes
download it from their site
www.us.playstation.com/PS3
here is a direct link to the latest update 2.53
http://www.us.playstation.com/Support/SystemUpdates/PS3
Grab the update from here:
http://uk.playstation.com/ps3/
(Obviously change the UK bit to suit your country)
Then on your USB drive put the update.pup file in:
USBdrive/PS3/UPDATE/update.pup
Needs to have the folder's in cap's for the PS3 to pick it up.
Then just go to "System Update" in the Setting's menu on the PS3 and choose "Update form External Drive"
Yes you can just go here download the update stick it on a usb stick & copy to hard drive if your from usa or any other country just change it up the top.http://uk.playstation.com/ps3/