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;
And at others...
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.