Charm customers into paying their bills. Struggling under the weight of past-due invoices? You aren't alone—with many companies hoarding cash, late customers are threatening the survival of many small businesses. The solution? The Wall Street Journal says get creative. If you alienate slow payers you could lose customers, collection attorneys are expensive, and if your customer goes bankrupt, you'll likely find yourself at the end of a long line. Instead, many small businesses are trying new ways of collecting the money, including using the personal touch, withholding services, being proactive in their collection methods, and negotiating new payment terms. Share your company's tricks at the WSJ blog Independent Street. Or check out Inc.'s tips for getting paid on time in a tough economy from entrepreneurs like yourself.

Class, please take out your iPhones, we're ready to begin. As entrepreneurial studies continue to take off in universities, TechCrunch reports the results of Stanford iPhone class, which has incubated some solid ideas for apps, including a Chinese-English/English-Chinese dictionary and an app that lets you map the locations of rental/sale properties from Craiglist and email or call the ad poster.

Geithner v. China. Along with apologizing for not paying his taxes, Obama's nominee for Sect. of the Treasury told members of Congress that the new administration believes China manipulates the value of its currency. Policy wonks disagree on whether the U.S. should take action or not. But for years officials have tried to broach the touchy subject with China and have supported its move in recent months to let the yuan appreciate against the dollar. The surprise today was Geithner's broad pronouncement that all countries should adopt flexible, market-based currency regimes and the forcefulness of Obama's position on the yuan, reports the WSJ. But before he can get to currency practices, Geithner says we the need to convince China to adopt a more aggressive stimulus package in concert with ours to spur domestic demand in both countries.

The recession hits search advertising. In anticipation of Google releasing its Q4 2008 earnings report at 4pm EST today, Peter Kafka over at AllThingsD takes a look at the one sector of the marketing world that was supposed to stay afloat: search advertising. CitiGroup predicts an increase in overall dollars spent on search (paid click growth), but a decrease in the amount spent on each ad (cost per click growth). Even without the report, the writing's on the wall for the search giant, says Kafka. Google has already been trying to "wring the extra pennies out of each visitor" with its YouTube affiliate program—if you're watching a Monty Python clip on YouTube, you might see an overlay ad from Amazon for a sale on a box set of DVDs appear on the bottom of the video. And the company announced lay-offs of full-time staff last week. Kafka's conclusion: Google is still "an awesome money-making machine," but no company or marketing strategy, not even search ads, are immune to the times.

Cash flow equals net worth. Dr. Jeff Cornwall of Belmont University (the author of the blog The Entrepreneurial Mind) has a thought-provoking post today on the recent decline in entrepreneurial wealth. Most entrepreneurs have their net worth tied up in their companies, and small businesses live and die on cash flow. As a result, low cash flow can mean shrinking personal wealth for entreprneurs. Cornwall has an interesting link to a rough calculation of the health of small companies by BizEquity.

Believe it or not, there are still some optimistic entrepreneurs out there. At least five of them by The New York Times' count. The paper found a handful of small business owners on Cape Cod who are remaining upbeat. From pest removal to home nursing, all admit facing challenges, but they're cautiously optimistic, and some have even seen growth. Stephen Sullivan—known as the "St. Francis of Cape Cod" thanks to his pet-care business, Feathers and Fur—insists, "People who put their heart into their work always have work."