Wave Selection
Based on a suggestion and sample implementation from Joost de Valk a new, updated Shortwave bookmarklet allows you to select text and have it automatically used as your search term. Now all you need to do is select some text, invoke Shortwave, type a trigger and hit enter. (Don’t forget that in Safari the items in your bookmark bar are mapped to ⌘+[1-9].)
As with the last update, this change couldn’t be made on the server-side so if you want this new functionality you will need to grab/create an updated bookmarklet.