Internet ad spending took the last year off and took four of Google's ( GOOG) top sales executives with it. Investors will be looking at Google's second-quarter earnings report after the bell today for signs that maybe online advertising, at least, has come back to work. Google, the leader in search with 64% of the market, has an uncomfortably tight relationship with the rise and fall of keyword queries and placement of ads near search results. Rivals Yahoo! ( YHOO) and Microsoft ( MSFT) have held firm in the downturn and introduced flashy new services to loosen Google's hold on the search market. Yahoo! rolled out a research tool called Search Pad that lets users keep notes and links in reference files. And Microsoft prettied up its Live search product with the vivid photo-centric Bing search site. For its part, Google has had little luck finding other avenues of trade outside search, though it did make a valiant effort this month with two new offerings. Last week, Google opened to the public its Voice service, which allows people to sign up for a new phone number and make calls on the Internet as they do with outfits such as eBay's ( EBAY) Skype and Vonage ( VG). And last week, Google announced its Chrome computer operating system plans, which are aimed directly at Microsoft's Windows franchise. The Web browser-based software, which will be available in one year, is intended to run so-called netbook or mini-notebook devices initially.