Background on Rudy's businesses
Patrick Healy and Russ Buettner at The New York Times have a useful primer on Giuliani's post-mayoral business empire, though not without the usual Times snarkiness. (For a good discussion of the Times' habitual disrespect for Giuliani, see this.)
For instance, Healy and Buettner opine "But, at the same time, [Giuliani's business] aspirations have been modestly realized: a collection of boutiques more than an empire ..." Since Giuliani's companies are private and release no financial information, the journalists don't say how they judge "modesty." They also supply no quotes from Giuliani or his partners suggesting that "empire" has ever been a goal.
Giuliani's ability to start three firms in six years while maintaining a lucrative speaking career is a testament to his energy and executive ability. In the discussion of the "lost campaign dossier", I have been amused to read many commentators who count Giuliani's business activities as one of the personal "scandals" he has to overcome. Private sector success is not a character flaw in the eyes of the American electorate (least of all among Republicans). As a corollary, voters in the private sector understand that losing a client or even a failed venture doesn't necessarily indicate incompetence or malfeasance -- American business is competitive and market conditions change.
The article discusses three firms: Giuliani Partners, Giuliani Capital and Giuliani Security and Safety. It also mentions but does not discuss Giuliani's speaking career and the Houston-based law firm Bracewell & Giuliani. Giuliani became a partner with the latter in spring 2005, lending his name and a network of contacts to the firm as it opened a New York office. Giuliani's role in the firm may be limited by other commitments, but he was still plugged in enough to discuss the venture in detail with the Dallas Business Journal last year.
Healy and Buettner spend a good deal of time on worthless speculation whether these businesses could survive a Giuliani departure. Memo to the Times: if Giuliani is president, those business will do just fine (associates of sitting presidents tend not to lack for clients -- just ask the Rodham brothers). If Giuliani isn't elected, then he doesn't have to leave the businesses.