Social search service Aardvark is considering accepting a $30+ million offer by Google, say multiple sources close to the companies (one source says it’s $40 million). The company, which was founded by ex-Googlers, has raised around $6 million in venture capital to date.

The company is also talking with other potential buyers, say our sources. And even if no one else comes to the table, they have a difficult decision to make. At least one venture capitalist has offered to put new money into the company at a similar valuation, and the founders may be in a position to sell some of their personal stock in that round as well.

So the decision comes down to sell now and take the guaranteed money, or roll the dice and go for the big win.

This is a fairly common situation. Automattic (the creators of WordPress), for example, turned down a $200 millionish offer to be acquired in 2007 and instead raised a new round at a similar valuation, taking money off the table for founders/execs.

Aardvark lets users ask their friends and others for advice and information. They recently launched a website version of the service as well.