<p>Is there an Eclipse command to surround the current selection with parentheses?</p>

<p>Creating a template is a decent workaround; it doesn't work with the "Surround With" functionality, because I want to parenthesize an expression, not an entire line, and that requires <code>${word_selection}</code> rather than <code>${line_selection}</code>.</p>

<p>Is there a way that I can bind a keyboard shortcut to this particular template? <kbd>Ctrl</kbd>-<kbd>space</kbd> <kbd>Ctrl</kbd>-<kbd>space</kbd> arrow arrow arrow isn't as slick as I'd hoped for.</p>

Easy, Window->Prefs, then select Java->Editor->Templates
Create a new template with : (${line_selection}${cursor})
The "line_selection" means you have to select more than one line.
You can try creating another one with "word_selection", too.
Then, select text, right click, Surround With... and choose your new template.