NB: The reason I asked about this is..

I have an object in some controller-ish/test-classish code. Doing $foo->something every other line became tedious. $foo was my star object for interaction, so wouldn't it be nice, similar to Test::More, to have ok(...) available.

The hitch is, $foo is a stateful object, so my class would need to be a singleton. So for some cases, it'd be nice to use my class as

$foo = Foo->new; 
$foo->bar; 
$foo->baz;
[download]

And at others...

use Foo::ExportedOrSomethingClever;
bar();
baz();
...
..
[download]

If the state got in the way and I could not separate things, I could go back to my first example. Ambrus is right, this shouldn't be used all over the place. State plus namespace clashes are a pain.