LenS wrote:
I've seen TV commercials for a portable, battery driven soldering tool
whose tip supposedly produces enough heat to solder small joints
almost instantly, and then, almost as quickly, cools enough to touch.

A tool like that would be very handy for me around the house if it
works as advertised. Has anyone actually seen or used one of these
tools?

Do you have a link to this device? It's operating window sounds rather
narrow; it probably is only sized to solder demonstration joints

Because there is no "standard" soldering job, there are several different
sized tools available from a pencil tip soldering iron for electronic work
to a torch for pipe sweating. IMHO your money is better spent on a regular
soldering iron for smaller home stuff and a gun for the bigger things, and a
torch for the plumbing jobs.

Like most things, you get what you pay for.