On Sun, 6 Dec 2009 08:21:31 -0800 (PST), John wrote:
I'm looking to buy a new LCD TV (42" to 50", haven't quite decided
yet), and I know enough not to buy accessories from the local
electronics store (Don't get me started on HDMI cables...). So, I'm
looking to build a custom wall mount. I'm thinking aluminum l-bars.
I'm wondering if anyone has any experience and can contribute some
do's and don'ts on the subject.

Why custom? Who's going to look at it? Get the cheapest commecial
mount that has the features you need. Most people do just fine with a
$60 wall mount which is little more than two brackets: one for the
TV, one for the Wall that hook together.