TripIt is fantastic. Everyone should have it on their phone, even if they just make one or two leisure trips a year. TripIt Pro is well worth the price if you regularly travel for business too, but just the free standard app is great. It's an itinerary planner, but really so much more. Just forward the confirmation emails for your bookings and BAM! It's automatically added to your itinerary.

Pro has features like price checking after you've booked, so you can rebook and save money if the price drops (and your cancellation terms allow). Another nice feature of Pro being all your frequent flyer/hotel/car program info in one place. It's also very good at informing you about flight changes, so rather than you checking the flight status, TripIt tells you as soon as possible, which gives you a better chance to react.