Laptop HDD about to crash!! HELP

[dudi]

I'm a newby and I need some help, my laptop has three days displaying a message something like this ...

Your HDD is malfunctioning, please backup immediately, total failure is imminent

So I've tried averything in my power, ran Windows Scan disk and tryed to fix the errors... not good, and the computer is getting slower and clumsier as the time passes...

I've decided to change the HDD of my laptop... ( am I right???), so I've researched about what I have and what should I replace it with.. and here comes my problem...

I have a Sony VAIO PGC-r505tl, with a Hitachi 15 Gb IDE HDD 2.5"...

Check out some online store, don't seem to find IDE drives...

My questions:

1) Can I use any other technology?
2) Can I upgraqde my laptops config to manage any other tech (such as ATA-6)?
3) Is there any way to find a reasonable affordable part to replace the bad one?

4) I'm I missing something, is there something I can do before replacing teh HDD?

ThankS