Well lucky you lee7. Here is what I have experienced both before and after 9/11:
I have never tried bringing a bare hard drive (do you mean to use it as a player somehow? If so how about a link to how it is done?) but i have brought other stuff on. Whether it is a camera, computer or just a radio, bring it on yourself. Once you are in the terminal, you can often watch the luggage handlers loading your plane out the window and they pretty much just grab stuff off of the rolling cart and hurl it at the airplane. If you want to get stuff back in the same number of pieces that you brought it into the airport, hold onto it.
The only exception is small metal bits like change, belt buckles, lighters, etc. For that stuff, have a piece of luggage with a small zippered compartment that you can dump stuff into just before you check it in.
Now, for cameras, radios and other small stuff, just leave it in your bag and let it get xrayed. Despite what anyone has told you, there is nothing in anything that is xray sensitive. I have even brought loaded cameras through carry on and the film has survived the trip. If you are going to travel with actual xray film, then ask a radiologist what to do but apart from that, there is no bad magic to deal with.
For laptops, they don't tend to want them being xrayed. Most of the older laptops out there used a sheet of metal that was more than half the size of the whole unit as a heat sink and sheets of metal can be used to hide stuff from xrays. Probably, most modern lappys with heat pipes would not have that issue but the powers that be have no way of knowing what lappys have what for cooling so they all get the same check. They are going to pull it off the line and check it with one of a few different technologies. Don't worry about it and don't ask too many questions. You can always google for stuff when you get home if you really feel the need to know what they did.
Also, don't bother locking stuff. It is not like the locks that most luggage come with are anything other than total cheese-ball stuff anyway. The handlers can open most bags with a fork if they really wanted and they could probably re-close it so that you would never know. Locking stuff just makes you a general PIA for the baggage screeners. And trust me on this one: you would rather they just get into your stuff and get out of it without getting annoyed if you don't want your stuff taped to a letter saying “whoops! Tough s**t deal with it.”