Investors concerned that economic uncertainty will extend into 2008 sent the markets tumbling to a lower close on the last trading day of 2007 with the Dow plummeting 101 points to 13,265. Nasdaq skidded 22 points to 2652.

On the upside

Towerstream (Nasdaq: TWR) named Jeffrey M. Thompson to the position of chief executive and president.

Vonage Holdings (NYSE: VG) and Nortel Networks (NYSE: NT) settled their patent suit by agreeing to cross license each others' technology. No payments will be made by either company.

LL&E Royalty Trust (NYSE: LRT) will not issue a trust income distribution for January 2008 and announced the termination of the trust.

On the downside

After the stock price more than doubled in 2007, shares of Apple (Nasdaq: AAPL) slipped as investors took profits.

Shares of Research in Motion (Nasdaq: RIMM) dropped as investors locked in profits.

Falling chip prices along with concerns that sales will miss expectations weighed down shares of chip maker Nvidia (NYSE: NVDA).

In the broad market, declining issues outpaced advancers by a margin of more than 10 to 9 on both the NYSE and Nasdaq. The Russell 2000 which tracks small cap stocks dropped 6 points to 766.