A brief note — today Zipcar filed an amended S-1 today with the Securities and Exchange Commission as part of its plan for an initial public offering (IPO). A total of 8,333,333 shares will be available at the IPO (some to be sold by the company and some by current shareholders) at an expected range of $14 – $16 per share. The company is hoping to begin trading on NASDAQ on April 14 (according to peHUB) under the ticker symbol ZIP.