With Join.me, you can share your Windows PC or Mac's desktop with up to 250 people over the Internet, a nifty trick that's useful for conducting presentations, engaging in collaborative brainstorming or seeking troubleshooting help from distant geeks. The free version is one of the Web's great bargains. (Many people will find it a viable alternative to fancier paid services such as WebEx and GoToMeeting.) And the utter simplicity — setting up a sharing session takes just a few clicks and requires no registration — is as appealing as the price tag.