Here are some highlights from this past week's earnings coverage from BloggingStocks:

• Archer Daniels Midland Co. (NYSE: ADM) said Q4 profit plunged, missing analysts' expectations.
• Berkshire Hathaway Inc. (NYSE: BRK.A) posted yet another solid quarter and topped analysts' expectations.
• Cisco Systems Inc. (NASDAQ: CSCO) reported solid results and reaffirmed its revenue guidance.
• General Mills Inc. (NYSE: GIS) performance despite rising commodities costs impressed Jim Cramer.
• Hansen Natural Corp. (NASDAQ: HANS) Q2 earnings surged on popularity of Monster energy drink.
• Humana Inc. (NYSE: HUM) beat Q2 expectations, sending shares of health insurers higher.
• LeapFrog Enterprises Inc. (NYSE: LF) narrowed its Q2 loss, sending shares up near its 52-week high.
• MGM Mirage (NYSE: MGM) Q2 profit tumbled but revenues topped analysts' expectations.
• NetSuite Inc. (NYSE: N) cut its Q2 loss and revenues surged on 400 new customers.
• Orbitz Worldwide Inc. (NYSE: OWW) narrowed its net loss while revenues inched upward.
• Polo Ralph Lauren Corp. (NYSE: RL) easily topped Q1 expectations and raised its full-year guidance.
• Pzena Investment Management Inc's (NYSE: PZN) CEO admits that its Q2 was "awful, just terrible."
• 3Com Corp. (NASDAQ: COMS) raised its Q1 profit and sales forecasts due to gains in China.
• Toyota Motor Corp. (NYSE: TM) net income fell due to the strong yen and rising materials costs.
• Warner Music Group Corp. (NYSE: WMG) reported a smaller-than-expected Q3 net loss.
• World Wrestling Entertainment Inc. (NYSE: WWE) flat year-over-year earnings fell short of estimtates.

MOST NOTEWORTHY: DiamondRock Hospitality, Pzena Investment and Vodafone were today's noteworthy upgrades:

• DiamondRock Hospitality (NYSE: DRH) was upgraded to Outperform from Neutral at Baird, citing the newly-announced 4.8M repurchase plan, strong balance sheet and valuation.
  
• Keefe Bruyette upgraded shares of Pzena Investment (NYSE: PZN) to Market Perform from Underperform after the company announced February ending AUM.
  
• Goldman added Vodafone (NYSE: VOD) to its Conviction Buy List following the recent weakness as they expect the company to benefit from growth in wireless data.

OTHER UPGRADES:

• UBS raised Weyerhaeuser (NYSE: WY) to Buy from Neutral.
  
• Credit Suisse upgraded MedCath (NASDAQ: MDTH) and Lululemon (NASDAQ: LULU) to Outperform from Neutral.
  
• Goldman added Cardinal Health (NYSE: CAH) to its Conviction Buy List.

Richard Pzena, the founder and co-chief investment officer of Pzena Investment Management (NYSE: PZN), is a top-notch value investor.

He knows that a long-term philosophy is the best approach. That is, it's never easy to invest in troubled companies -- and to get the timing right (actually, Pzena had a particularly tough year in 2007). But the rewards can ultimately be very satisfying.

Interestingly enough, Pzena's also an expert on financial stocks. And, yes, he thinks there are big-time opportunities in the sector (this is according to a piece in Barron's, which is a paid publication).

So what does he like? Well, he's bullish on Fannie Mae (NYSE: FNM) and Freddie Mac (NYSE: FRE). Basically, he thinks both companies will be the main beneficiaries of the mortgage collapse. He believes that the recent losses have been the results of accounting -- not real cash losses. Keep in mind that these companies had little trouble raising large amounts of capital.

Pzena is also a fan of Citigroup (NYSE: C). After all, the company has a diversified global platform. For example, in the emerging markets, there should be lots of growth opportunities (such as with credit cards and consumer loans).

Tom Taulli is the author of various books, including The Complete M&A Handbook and The Edgar Online Guide to Decoding Financial Statements. He also operates DealProfiles.com.

Pzena Investment Management (NYSE: PZN) got its start in 1995 -- and has been quite busy since then. These days the firm manages about $30.6 billion.

In fact, today the company hit the public markets in a successful IPO. Pzena priced its offering at $18, which was at the top of its $16-$18 range. The underwriters include tier-1 firms Goldman Sachs (NYSE: GS) and UBS Investment Bank (NYSE: UBS).

Pzena's investment approach is on the value side. What's more, the firm is a big believer in providing high-end services. Then again, the clientele tends to be fairly affluent.