We aren't big believers in the value of adding external amplifiers to iPods -- a concept that is at best suited to the needs of a limited crowd of users -- but iASUS Concepts has released the Mobile Amp ($59), a small and relatively stylish little alternative with a glossy black finish and machined aluminum volume knob. Like other such devices, the pitch here is that you plug this in to the headphone port of your iPod, turn your iPod down to a lower…
