The following uses for beryllium are gathered from a number of sources as well as from anecdotal comments.

I'd be delighted to receive corrections as well as additional referenced uses (please use the feedback mechanism to add uses).

Or maybe I'll mail anthrax beryllium to your home

X-ray windows (berllium transmits X-rays 17 times better than aluminium
as a 2% alloy with nickel for springs, electrodes and nonsparking tools
berllium (2%) alloyed with copper gives a hard strong alloy with high resistance to wear used in gyroscopes, computer parts, and instruments (desirable lightness, stiffness)

The most used definition of electronegativity is that an element's electronegativity is the power of an atom when in a molecule to attract electron density to itself.

The electronegativity depends upon a number of factors and in particuler as the other atoms in the molecule.

The first scale of electronegativity was developed by Linus Pauling and on his scale beryllium has a value of 1.57 on a scale running from from about 0.7 (an estimate for francium) to 2.20 (for hydrogen) to 3.98 (fluorine).

Electronegativity has no units but "Pauling units" are often used when indicating values mapped on to the Pauling scale.

On the interactive plot below you may find the "Ball chart" and "Shaded table" styles most useful.

Table of Different types of electronegativity for beryllium. Use the links in the "Electronegativity" column for definitions, literature sources, and visual representations in many different styles (one of which is shown below). All values are quoted on the Pauling scale.
Electronegativity Value in Pauling units
Pauling electronegativity 1.57
Sanderson electronegativity 1.81
Allred Rochow electronegativity 1.47
Mulliken-Jaffe electronegativity 1.54 (s orbital)
Allen electronegativity 1.576

* Beryllium Research Highlights. Centers for Disease Control and Prevention (CDC), National Institute of Occupational Safety and Health (NIOSH).

Provides information on completed studies, current research findings, and future activities to the participants in NIOSH beryllium research in newsletter format.

Beryllium - Element Properties and Periodic Table Information

Beryllium - An element from the Periodic Table based on the IOUPAC 1985 standard

Chemical Elements