Is there any Monday tougher on the spirit and/or to-do list than the one at the very tail-end of December? It seems like every person you need to talk to, in order to get your job done, is away on vacation, including half your team, your boss, and 90 percent of your clients. (The 10 percent who need something from you, unfortunately, are at their desk and raring to go.) The good news is that we have the collective wisdom of Twitter to advise us in our time of trouble. Here's how to get stuff done today, and every day during the year to come.