A number of exchange-traded funds gained ground for the week, and those tracking energy and oil ranked among the best performers.

The Oil Service HOLDRs ( OIH) rose 3.9% over the past five days, and the PowerShares Dynamic Oil & Gas Services ( PXJ) fund tacked on 4%. The iShares Dow Jones U.S. Energy Sector ( IYE) and Ultra Oil & Gas ProShares ( DIG) spiked 4.3% and 7.9%, respectively.

While crude oil saw erratic day-to-day movements, repeatedly hitting new record highs before succumbing to profit-taking, in the end it reaped gains for the week, ending at $126.29 a barrel.

Among energy stocks, Exxon Mobil ( XOM), Chevron ( CVX) and ConocoPhillips ( COP) added 3.1% or more.

Gold also had a good week, as futures on the metal lifted to end the week just shy of $900 an ounce. Since Monday, the Market Vectors Gold Miners ETF ( GDX) ramped up 3%. The iShares COMEX Gold Trust ( IAU) and the streetTRACKS Gold Trust ( GLD) rose roughly 2% apiece.

Various corners of the tech sector were also on the rise amid a series of uplifting news items. Research in Motion ( RIM) kicked off the week by releasing its new BlackBerry Bold smartphone product, which is seen as a possible rival to Apple's ( AAPL) iPhone, and RIM shares ended up 5.3% for the week. Apple climbed 2.3%.

The Wireless HOLDRS ( WMH) fund climbed 3.1% over the past five days, and PowerShares Dynamic Telecom & Wireless ( PTE) moved up 4.7%.

Also, the Vanguard Information Technology ETF ( VGT) climbed 3.8% during a week in which Hewlett-Packard ( HPQ) inked a deal to take out Electronic Data Systems ( EDS) for $13.9 billion. EDS shares propelled 29% higher for the week. H-P lost 3.8%,

In more merger-related tech news, CNET ( CNET) agreed to sell itself to CBS ( CBS) for $1.8 billion. CNET shares have soared nearly 50% since Monday, and CBS surrendered 4%.

Elsewhere, activist investor Carl Icahn built up his position in Yahoo! ( YHOO) before moving to replace 10 of the company's directors, saying in a letter that the firm "acted irrationally" in turning down Microsoft's ( MSFT) sweetened buyout bid.

Yahoo! shares have ballooned 6.7% over the past week. The Internet HOLDRs ( HHH) fund jumped 4.7%, and the Internet Architecture HOLDRs ( IAH) ratcheted up 2.5%.