It’s easy to get caught up in the excitement of Web 2.0 when you start reading headlines about people starting unique new businesses that make tons of money.  But lest we forget the waterglass analogies of the past, here are 10 key perspectives from the "glass is half empty" side of the equation. 

1. We learned our lesson last time. And we’re going to cash out before this bubble pops.

2. This is not a bubble. Hot parties, overheated PR pitches, and five or six dozen social networking sites are just healthy indicators of a new boom.

3. It’s all about community and sharing. But we told our venture capitalists that our exit strategy will make them rich. (Corollary: But you have to know someone to get into our conference/party.)

4. Online advertising will pay for everything. As if click fraud is any kind of a threat.

5. These sites are so easy, my mother could use them. And they’re so geeky, she has no interest in even trying.

6. The analysts are trustworthy now. Like the one who said MySpace will be worth $15 billion in a few years — or was that the one who said Amazon was worth $400 a share? Whoops, I’m mixing my bubbles.

7. There’s no glut of social networks — young people are always up for trying something new. And we’re happy to share in the 17 percent of them who aren’t glued to MySpace.

8. Our site is still in Beta. And it won’t be out of Beta until we figure out how to make money from it, or sell it to Google, whichever comes first. (Paraphrased from Ivor Tossell‘s piece in Canada’s Globe and Mail newspaper.)

9. We’re different from all those other sites. But we have a silly name, open APIs, some flashy Ajax technology, and other features just like the rest of them. (Thanks again to Tossell.)

10. We look forward to working with our new partners at Google. Take the money, hand over the keys and step aside. Larry and Sergey are driving your bus now.

More here.