> Get info for multiple files in one window

This is mostly useful for finding out how much disk space is taken up by several different files, without putting them in a folder together or moving them around.

Select the files in the Finder, then, instead of Command-I (Get Info), use Control-Command-I (Get Summary Info).

> Fail to use the new iMac as a TV

In case you heard about the fact that Apple's new 27" iMac can also double as an external monitor, and you were getting excited about all the different kinds of devices you can attach to this thing — don't. The iMac will only accept DisplayPort input. This 'feature' is designed not for your convenience, but to promote an Apple-favoured standard with little prior presence in the marketplace. DisplayPort might eventually achieve wide adoption, but by the time this feature becomes generally useful, your iMac will almost certainly be obsolete.

> Avoid guest accounts on Snow Leopard

Using guest accounts on Snow Leopard could cause your entire main account to be wiped. That's right — wiped. Still feel comfortable out there on the bleeding edge?

> Bank on Apple's nonexistent credibility

Erm. Something tells me that Apple — a company whose name is becoming increasingly synonymous with corporate censorship and interference with interoperability for user control — is unlikely to win any kind of widespread consumer support for its new universal connection standard. Rather, the best survival chance for any new interoperability protocol would be if it weren't mentioned in the same breath with the name of the most notoriously willful foe of interoperability of the 21st Century.