Lots of things have changed from my entry so many years ago. Specifics kill your time spent on more important matters. NEVER "sure" but I still stay with the flow.
Exceptions aside, my 'rule of thumb' stands in consideration of the level of risk I am accepting by investing in a company's stock. While I may, semantic wise, still be investing in a penny stock at $2, I assure you that I consider it to have far less risk than if its share price was $.01. At the $2 level, I am very content to believe I am no longer investing in a penny stock.