Select text-replacement without adding a space?
I don’t know how to do this with Lion’s text replacements, but you might want to consider TextExpander, which performs a similar task. You don’t need to add a trailing space to open a snippet, which is what you’re looking for, right? e.g. my email address in TextExpander is set off with the shortcut ;g, no space required. 

[Duped from comments per dan8394’s request]