The ref function will tell you what class you're blessed into, if that's what you want.

package Foo;
use overload '""', sub {"Hello, World!"};
package main;
my $foo = bless {}, 'Foo';
{
    local $, = ' ';
    print $foo, ref($foo), $/;</p>
}
[download]

Otherwise, you'll probably want to rebless into another class without the overloaded stringification. I can't think of a way to completely unbless an object.

UpdateL BrowserUK++, I completely forgot about that.