(possible subtitle: Or, what's the difference between Twitter, Sharepoint and the iPod.)

Jay's Rule #1: At any given time, a tool has, at most, two features that don't annoy you. The rest do (they're in your way, or too hard to reach, or you can't figure them out, or they don't work the way you want, etc.).

Corollary 1: Tools with a few features tend to be less annoying. E.g., a tool with 5 features might tend to have an annoyance factor of about (5-2)/5, or 60%.

Corollary 2: The more features a tool has, the more totally and amazingly annoying it can be. E.g., a tool with 500 features might tend to have an annoyance factor of about (500-2)/500, or 99.6%.

Jay's Rule #2: The rare tool that is brilliant and beloved finds some way to break Jay's Rule #1, and gets you an extra 1-2 features that actually don't annoy you—at least most of the time (so, bringing the total to as many as 4 features that don't annoy you). E.g. the rare and brilliant tool with 5 features might tend to have an annoyance factor of (5-4)/5, or 20%.

***

Footnote 1: While people often do seem to need a tool with a lot of features (that suggest Rule #1 / Corollary 2), they usually only need a select set of simple tools taken from a much larger set of potentially needed simple tools (all of which match up with Rule #1 / Corollary 1 or Rule #2).

Footnote 2: The annoyance factor associated with a tool has a complex interrelationship with the annoyance factor associated with the tool's users. For example: even great tools, in the hands of annoying people, can be used in annoying ways (e.g., blogs); or, even great people can seem annoying when using a tool's annoying features (e.g., blogs), etc.

;-)