I have the Baby Trend Sit N Stand Plus Double stroller for my 2 year old and my 5 month old. It has been a life saver! Very easy to use, accommodates a baby carrier for the infant, folds quickly with one hand.
The only negatives I have seen are:
1)It is really tough to get up curbs or other sidewalk bumps. I either have to use all my body weight or go around to the front and lift it. If you can find a model with larger wheels, the curbs and bumps won't be as much of an issue.
2) I wish the seats gave the option to face each other since the baby loves to watch her big brother and would rather look at him than the scenery (well, they face now with the carrier, but won't once the baby is sitting in the stroller itself).
3) The storage underneath is a bit tough to access. It can accommodate a large diaper bag easily with room to spare, but it is tough to get things in and out of the compartment.
This stroller can be found at target.com or walmart.com along with a few other random baby websites. Look for a place with either site-to-store or free shipping. It is not worth paying the huge shipping fees on a large item like this when there are other ways to get it.