Tembo implements a service to create a new search window. This makes it easy to start a Tembo search upon a single keystroke. Just follow the instructions from the Tembo > Preferences > Shortcuts to the Keyboard System Preferences Pane. There you may assign a hotkey to the "Search in Tembo" service.
If you want more flexibility, you may use AppleScript to launch Tembo:
1. Download the LaunchTembo script
2. Move the script to ~/Library/Scripts/
If you wish to assign a hotkey to the script:
3. Download and install FastScripts (free for up to 10 keyboard shortcuts)
4. Set your hotkey in FastScripts