Everybody needs diagrams. Most users need to create one more often than they think: that flowchart for a presentation, that sketch of the bird feeder to build this weekend, or a time line.
Getting more technical, there are always circuits and blueprints and the like. Stop wasting time with an office app, the GIMP, or a paint program: use Dia, an easy yet powerful made-for-diagrams editor.

Including Dia in this series is just a bit of a stretch, because it is not a conventional "vector graphic editor". Instead, Dia operates at a somewhat higher level of abstraction. But since that abstraction is very appropriate for dataflow diagrams (such as the one I picked as a comparison project), I think it's important to note what it can do.

"I thought Ligaya Turmelle's post on SQL joins was a great primer for novice developers. Since SQL joins are fundamentally set-based, the use of Venn diagrams to explain them seems, at first blush, to be a natural fit. However, like the commenters to her post, I found that the Venn diagrams didn't quite match the SQL join syntax reality in my testing..."

Richard Matthew Stallman, also known as The Last of the True Hackers, invited for a talk at FRHACK 01, an International IT Security Conference by hackers, for hackers - France, September 7-11, 2009 ...

OpenOffice.org's tools for creating diagrams are easy to ignore. For one thing, their controls are extremely small. For another, they are pitifully under-documented in the online help, which plods through the options without explaining what they are or why you want to use them.

Some of the most fascinating, fun and influential tech devices of all time are based on Linux. Our gadget geek names 10 of the best.

At the CanSecWest security conference in Vancouver BC, hackers were invited to find and exploit holes in modern browsers. A popular target for hackers at this year’s conference was Safari on a Mac — definitely the lowest hanging fruit.

"Chumby, a venture-backed San Diego startup, is readying a soft, leather-covered Linux-powered gadget conceived as an Internet-era replacement for clock and table radios."

ESR: "These are people (mainly adolescent males) who get a kick out of breaking into computers and phreaking the phone system. Real hackers call these people ‘crackers’ and want nothing to do with them.