Facebook applications are buying each other? No, seriously? For $60,000 a pop?
When one business-model-free, revenue-free, loss-making company buys another business-model-free, revenue-free, loss-making company, you know the bubble is well and truly on.
Relatedly, in Alert #3 I predicted that on current trends, a Bubble 2.0 company is due to be bought for 24x revenue sometime in September. Business.com is currently tipped to sell for exactly that multiplier; let's see if I get the date right as well.