Lets start simple before we get carried away:
1) Does the drive spin up when you power on the unit?
2) If it does spin up, does it make any noises? Clicking, banging, scratching, anything other than normal hard drive noises?
3) You say it's an external disk, is it in a cady you can easily open with a screwdriver?
4) Do you have access to a hard drive dock, or to another hard drive caddy?
I can give more specific advice when I see the answers to my questions, but I can give some general tips regardless.
Firstly, start with all possible non-destructive techniques, then, start with semi-destructive techniques, and then finally go for desperate measures.
If the drive is powering up, then you can try to use software like SpinRite (
http://anonym.to/?http://www.grc.com/spinrite.htma) to get your data off. If SpinRite gets the drive up and working again DON'T DELAY, GET YOUR DATA OFF ASAP, AND DON'T POWER THE DRIVE DOWN TILL YOU HAVE ALL YOUR DATA.
If the drive is not powering up it could be for two reasons with an external. Either the drives is bust, or else the caddy (case) is. Either way, you need to get the drive out of the caddy if it's not powering up. Some caddies are easy to take apart, others need to be broken open. What ever you do DON'T HIT THE CADDY TO GET IT OFF THE DRIVE. I've found that slowly wedging the sides apart at the seams with a big flat screwdriver usually works.
Once the drive is out you need to try to get it connected to a computer, you have three options:
1) use a hard drive dock (if you have one this is the simplest and best solution)
2) use another caddy - if you have one, great, if not, they are cheap to buy
3) open the case of your computer and see if you have a spare SATA (or IDE) channel on your motherboard you could connect the drive to
If the drive can be read when connected to a computer by one of these ways then it was not the drive that died but just the caddy, so you can go ahead and make a backup and then buy a caddy to hold the drive from now on.
If the drive still can't be read when it's bare, then it really is the drive that's dead, and then you have to accept that there is a high probability that the data is lost. You can throw time or money or both at it, and you might get it back, but there are no guarantees.
Hard drive recovery is EXPENSIVE. VERY expensive. If you can afford to spend a grand or more, then the best thing you can do is go straight to a drive recovery company before you try ANYTHING yourself - you are as likely as anything to do more damage if you poke at it!
If you can't afford to spend thousands of dollars on recovery, THEN it's reasonable to try to recover the data yourself through destructive methods.
If the disk died from a head-crash, then sticking it in the freezer has a reasonable chance of working - I've seen it done successfully a few times. BUT BE WARNED, YOU GET ONE SHOT ONLY, THE MOMENT THE DRIVE SPINS UP, GET YOUR DATA OFF - THE DRIVE WILL ONLY RUN THIS ONCE, AND NOT FOR LONG! What ever you do, if you've frozen it and it starts up, do not turn it off, don't waste a millisecond, start copying data like mad - the drive will not work for long, and if it stops, it is exceptionally unlikely to ever spin again!
If the disk has died from a dead logic circuit, then you can try to find an identical working drive on ebay or what ever, and I do mean IDENTICAL, and then very carefully de-solder the old board and remove it, and solder in the new board. This is only an option if you know how to wield a soldering iron!
I hope some of that is of help to you.
The key lesson here though is simple - everyone should always back up all data they care about! If it doesn't exist in at least two places it doesn't really exist, that's how you should look at data!
I hope everyone reading this thread does a backup tonight, and never long-fingered it again. Remember, it's not a question of IF your hard drive will die, but WHEN!
B.
now i am looking for an repair service that is very discrete because there are private vids of me and some others which i do not want to be seen by strangers. 
