1. Chicco Polly Magic Hair chairs for 0 months to 12 months plus (suitable til 3 years) have been godsend. For babies from 0 to 6 months of age it can be used as a baby chair: it has a detachable ring with toys to play and stimulate. For babies from 6 to 12 months of age, it can be turned into a highchair to help baby through the weaning phase. The detachable tray is adjustable to 4 positions to adapt to the growing child. From 1 to 3 years of age, it can be turned into a normal chair, so that babies can sit with family. The backrest can be adjusted to three different positions and the seat to six different heights. (and if you have indoor pets like dogs, these chairs are convenient)
2. My Jane Power Twin stroller. LOVE IT! It is small (it fits at the back of a Toyota Yaris) and comes with carseats.
3. Swing: If you're busy feeding the one twin and the other starts crying, you can always put them in a swing to guarentee a peace of mind. Other props that help calm babies include bouncers, soothers and eventually jumperoos.
4. Bathing chairs: I cannot even begin to tell you how much time I've saved with the the bathing chairs.
5. Slings and carriers: Most twin mummies don't think of getting a sling/carrier because you can't carry both babies at once, but I never leave the house without it when I'm with the babies in case one baby gets 'tired' of sitting in the buggy. It saves time because instead of dealing with a crying baby, I normally put him her in a sling and carry on pushing the stroller. The one shoulder sling does eventually hurt your shoulder as babies grow older, so I now use a Chicco Frontal carrier and I love it!
Other things that might or might not work for you are swaddlers, baby sleeping bags and white noise CD for babies to sleep longer (I wish someone had told me about this one while I was pregnant. It works wonders for us)