Linkorama

1. Catalyze is a new social networking site for people who design software, websites or user experiences.

2. An article from Wharton Business School's Knowledge@Wharton's newsletter is challenging the assumed efficiency in automatic recommendation systems found online, suggesting that they may be limiting the 'long tail' effect.

3. Bruce Nussbaum is reporting that some ad agencies are about to be sacked. No word on which companies might be sacking some agencies. Which suggests it might be a bit of a way off yet.

4. If you're an O2 customer, you might care to ask for more from them here. (Disclaimer: I wrote this, so I'd really like you to. And notice any grammatical infelicities.)