Note: I've tried searching for this in the PHP docs, but I can't figure
out how to make it search for the dollar sign; it simply ignores it.

I remember seeing the variable $_ used in some applications. Is this a
variable that is "special" in PHP, or do people actually define this
cryptic thing?

Also, how can this be of use to me?

And one last thing: How do I search (on Google or any other search
engine for that matter) with special characters. If I put in "$_ +PHP"
in Google, it gives very odd results, which leads me to believe that it
ignores special characters such as $ and &.

Thanks,
TekWiz