I'm not sure what 'hassle' would be saved - the drive would have an operating system on it, and it couldn't be used for any other purpose, or in any other machine - none of the software would run.
If you simply want to access data files on another computer you could do what I do - put them on a USB memory stick. I use an 8Gb version smaller than my car key which carries more than I will ever need when I'm on the move.
1/ physical security - one could put it in a fireproof theftproof safe. 2/a speedy backup method if you have a ' identicle twintwin 'hdd .. avoid need for timeconsuming imaging software. 3/useful backup especially for non-booting scenarios.
frazky, one reason you give is to put it in a fireproof/theftproof safe. Why not just put the laptop complete in the safe, then you wouldn`t have to keep disconnecting the hdd with the eventual bad connection occurring.
You want to remove your computer's drive whenever you like, so you can store it in a safe place - but why?
You would need to be storing some pretty important data to warrant keeping a drive in a thief-proof, fireproof safe, and there are much easier ways to do the job. Just write the data to a flash drive, or a CD/DVD and keep it somewhere apart from the computer. In a commercial context data is stored on removeable media which is taken off-site every night, or sent down a line to a dedicated, secure data storage facility. There's no need to keep taking hard drives out of laptops - if there was a proven need for it the manufacturers would already make the machines that way.
Smith told the Lords constitution committee that an example might be a doctor leaving a laptop containing personal details of patients in a car. It was “hard to say [this was] anything other than criminal negligence”, he said.