How to repair Mac partitions without Internet Recovery and Rescue USB?
There is not much you can do with a stock Mac to fix the hard drive.

You could plug the hard drive in another Mac (as a secondary drive, not a boot one) and see what Disk Utility tells you (press command-space then type Disk Utility to launch it) about it but it's not guaranteed to help you much. I am not even sure it can correctly repair a boot hard drive.

Your best bet is using a disk repair program such as DiskWarrior (http://www.alsoft.com/diskwarrior/).

It costs a bit but has a very good reputation and saved many damaged hard drives. Cf http://daringfireball.net/2010/03/ode_to_diskwarrior_superduper_dropbox for a great example of it saving important data.