The just-released Mailplane 2.1.6 from Uncomplex adds built-in support for the highly interesting Rapportive plug-in (see "Rapportive Plug-in Replaces Gmail Ads with Sender Info," 27 March 2010). Mailplane 2.1.6 also now works with the Share > Send via Mail menu items in the iWork '09 applications. With them, you can email your document via Mailplane in its native format or as a Word, Excel, PowerPoint, or PDF document. A few minor bugs have also been fixed, some of which were related to Gmail changes. ($24.95 new, free update, 6.7 MB)
Wake On Demand in Snow Leopard
Putting your Mac to sleep saves power, but it also disrupts using your Mac as a file server, among other purposes. Wake on Demand in Snow Leopard works in conjunction with an Apple base station to continue announcing Bonjour services that the sleeping computer offers.
While the requirements for this feature are complex, eligible users can toggle this feature in the Energy Saver preference pane. It's labeled Wake on Network Access for computers that can be roused either via Wi-Fi or Ethernet; Wake on Ethernet Network Access or Wake on AirPort Network Access for wired- or wireless-only machines, respectively. Uncheck the box to disable this feature.