Are We Headed For Another Tech Bubble?

Have you heard? Twitter is worth $1 billion. Right now, at least. The Web property du jour has raised more financing - $100 million, reportedly, for a valuation 10 times that amount. Twitter has yet to show any sort of profit and has no monetization path, and yet investors are stampeding to own part of the company. The flurry of activity has some wondering if we're headed toward another tech bubble, centered on social media and cloud services.