As Shantzu put it:
Bricked: The term "bricking" should only be used in the case where you get your phone in a state where it is inoperable AND you can not in any way repair it yourself.
In many cases your phone is not bricked. Common uses of the phrase bricked often include:
1. Boot looping
Try option a, b or c2. Not going past SGS logo
Try option a, b, or c3. BSOD (Black Screen Of Death) logo
Try option a or b4. Error Message: "Can't mount /dev/block/stl10 (invalid Argument)"
Try option dIn most circumstances your phone is still recoverable. Have a look below to see what you can do.
a. If you have the 3 button combo available then try the the download mode combo (Volume Down + Home + Power). If the phone is displaying the BSOD logo and you hold this combo for 10 seconds or so, with the USB plug in, you might just be able to get it into download mode (if you're lucky). If you get the charge screen, turn off phone and try again without USB plug in.If the above options do work, then what you need to do next is get odin up and running and flash with an appropriate firmware. There are a lot of straight forward guides out there if you don't know how to do this properly (which might be how you bricked your phone in the first place).
b. You can make this or buy one on ebay. It will set you back up to $10. Once you have the jig, have the phone off, plug it in and it should boot into download mode.
c. Use android debug bridge. There is a useful guide on how to get it working and how to use it to put phone in download mode here. This will only work if your PC is registering the phone as plugged in.
d. Use TechKidTarek's method here to restore correct booting.
I suggest you follow one such as this very closely. And, for the love of android, do not interrupt the flash process. This is the most likely way to make a $500 paperweight.
When all else fails, you may have to send it to samsung repair.
Last of all, good luck.