SEO: What's better .org or .net ?

I honestly don't think. Maybe in some cases when you target especially to certian market. For example if you're a big company and provide services, short if you're an organization, profit or non profit (although .com is made for profit organizations, so .org will be for non profit), then it'd be better to have domain name that actually represents your organization, thus .org. If you're on the other hand, ISP, or company that provides mainly internet and network services, the logical choice would be .net. I don't remember well, but I think google treats them the same. The only difference, is as I said, logic choice....