Glenn Fleishman explains a tiny tweak you can make in Lion that enables AirDrop peer-to-peer file exchange to work over local area Ethernet and wireless networks. This enables AirDrop for older Macs that lack the right Wi-Fi chips to work with AirDrop out of the box, and it also adds wired LAN access for even those Macs that do have supported Wi-Fi chips. follow link
Keep Markup Tools Active in PDFpen
By default, PDFpen switches back to the Edit tool each time you add text, scribbles or other markup. To keep a tool selected (continuous use mode), double-click it. To exit continuous use mode, click the Select tool or press Command-1. You can also make continuous use mode the default by selecting Keep Tools Selected After Use in PDFpen's Editing preferences.
Enable AirDrop for All Macs with Lion
Check out the Take Control ebooks that expand on the topic in this article: