When Linux hard drives go bad

[Duane Morin]

I think my laptop is dying.  For some apps (particularly mozilla) it goes 
into this weird hang mode where all I can hear is this rhythmic 
"kachunkachunkachunka" noise for many seconds.   Also some copy operations 
in the file system have failed with weird "IO errors".  Lastly and perhaps 
most importantly, sometimes when rebooting the machine it gives me a 
failure to check the file system.

Assuming for the moment that a new laptop is not in my future, is there a 
way that I can somehow detect and flag bad sectors on the drive?  Or at 
least determine which files use those bad areas so that I can work around 
them?  Mozilla is the primary culprit, but not the only one.

Duane