A six-year-old registered trademark, acquired by Cisco Systems after the 2000 acquisition of telephone equipment supplier InfoGear, and which applied at the time to a device no one would want today, may just now pay off for Cisco's consumer division. Linksys today announced it's attaching the iPhone trademark to its line of VoIP and Skype phones.

Back in August 2005, Linksys demonstrated its first series of wireless Skype phones, though Engadget correctly ascertained the CIT200 model wasn't really WiFi - that it actually transmitted over the 1.9 GHz band. Last May, during what could be considered the "first re-introduction" of Linksys' VoIP equipment in the US, the company presented its first real WiFi VoIP phone, the WIP300, this time with support for SIP v2 signaling protocol.

Now, a "second re-introduction" has re-christened the CIT200 as the "iPhone Cordless Internet Telephony Kit," and the WIP300 as the "iPhone Wireless-G IP Phone." Further, the CIT310 introduced to many in the press just last month -- a dual-mode cordless phone that flips between landline mode and Yahoo Messenger -- will get the "iPhone Dual-mode Phone" moniker. The CIT400, announced just weeks ago, a similar dual-mode device with Skype support, will receive similar branding.

This morning's announcement subtly emphasizes the "immediate availability" of all of these devices, though the fact is, many have been available under their less dynamic brand names for several months. Still, the announcement may have had its desired effect, as some news sources are treating this as a full-scale product line launch, and some retailers may very well carry on this message.

Not that this means there's a sale going on, as Linksys' estimated street prices for its iPhones appear to exceed their actual street prices in a check of the markets today, although this is the week before Christmas.

Some financial analysts' blogs were asking the question this morning of whether Apple saw this coming, and the immediate counter-question was: what makes you think they didn't?

Though "iPhone" may very well be the more attractive moniker, Apple filed an application to register the trademark "Vingle" with the US Patent and Trademark Office back in October 2005, in three parts: first to apply to wireless multimedia services, second, to wireless multimedia devices, and third to the stores, both online and retail, that sell and service them. A check of the USPTO database today shows none of those applications have been formally registered, nor do there appear to be any viable substitutes at present.