we had the same problem with our tall 2YO and didnt think the peapod or aerobed would work. Amazon sells a cheap play yard by 'dream on me' that looks like a pack and play but is several inches longer, and is about $70. lifesaver for us.

We have a tall 28 months old and we're still using a pack and play OK. He lays diagonally and it's fine. We'll do this a few months more and then jump off that bridge when we have to.

With my first, we used the toddler inflatable beds from One Step Ahead - I use the plural because we had to replace it on multiple occasions after it developed tears. And he tended to roll off it on occasion, despite the raised sides. The Aerobed version may be sturdier but I never found this a great solution. With #2, we planned to go the same route out of necessity, since like his brother he is 95% for height. But at 2.5yo he still prefers his crib at home, and despite being "too big" he still sleeps happily in a pack-n-play on the road. It's totally bizarre, since he can literally climb right out of it and he is long enough to touch both ends when lying down. On one recent trip we put him in a toddler bed that was available and it was a total disaster. Went back to the pnp with relief. I don't think it's true for all kids, but some obviously don't mind the size factor even when they look like they ought to.

For a toddler who isn't already used to a Peapod, I wouldn't bother trying it. We got one around 10 mos and have tried over and over to get now-20 mos DS to sleep in it since then (we have left it out for him to play in so he could get used to it, we have added better bedding, we have tried sitting next to him while he falls asleep, etc) and he just will. not. sleep. there. Total waste of money.
I would try the Pack n' Play again before the trip and see if the size is actually a problem. I've seen lots of babies sleep perpendicularly in their cribs, so feeling cramped clearly doesn't bother some...

We have a Bjorn travel crib, and my 21 month old figured out how to climb out of it. So, although it is supposedly for kids up to a certain age, it doesn't necessarily work. We spent a bunch of money on it under the assumption it would last a long time, and are disappointed in that. I think for our trip coming up, we may just try the aero bed or a mattress on the floor. My son still sleeps in a crib, so fingers crossed he actually stays in the bed all night. Good luck.

We have a pea pod plus, which is a travel tent/bed for a toddler. It got many good reviews on-line, but I think it scares my son. He is just 2, sleeps in a crib at home and when we travel with it, he wakes up in the middle of the night screaming the first night (probably confused - there is a tent over his head). Also he can't actually sit up in the tent. I think he would like that Baby Bjorn travel crib better, but I am not prepared to pay almost $300 for one more year of travel.

So it is light weight, easy to carry. He is a little too long for a pack and play. probably a good idea, but not every kid will love it.

try a pea pod! you can get them on amazon or at buy buy baby. we have two for our little ones (1 and 2.5) and they work great for keeping the younger contained.

http://www.onestepahead.com/catalog/product.jsp?productId=6091&parentCategoryId=85184&categoryId=85218&subCategoryId=86218

Travel Trundle. Our friends had one when we visited - loved it!

we used the toddler Aero bed that was mentioned above. My son was a little over 2 1/2 and it worked well.

We have also just taken the mattress off of a bed in a hotel room and put it on the floor.

Some of the European brand pack n play / portable cribs are longer and narrower than the Graco pack n play. My DD never liked sleeping in an aero bed - she preferred the feel of a crib.

We have the Baby Bjorn travel crib and my son loves it. He is six months old. However, the site says it can accommodate up to three years old. The padding is sufficient. The sheets do not fit a standard crib and are sold separately (not expensive -- found them on Target.com).

http://www.toysrus.com/product/index.jsp?productId=2924917

Try the youth aero bed. It's $49 on Amazon http://www.amazon.com/Aero-40010-AeroBed-for-Kids/dp/B00006IV33/ref=sr_1_1?ie=UTF8&s=home-garden&qid=1244599324&sr=8-1

We have it and it works great. It has a bit of a curve to it so the child can't roll off and it plenty big to last several years.

Twin air mattress and put on the floor.

Graco makes a pack n play that is SQUARE and bigger than the regular ones. It is closer to the size of those old fashioned play pens. My very large toddler sleeps in that with room to spare. We got ours at Amazon.com. Just checked and they are selling it for $78. It is 38 by 38 inches square. (Search Graco and Bugs)

We are taking a road trip later this month with DS who turned 2 in April. We have always used the pack n play, but I am afraid he may be too big. We are going to do a trial run this weekend, but does anyone have any suggestions for a travel bed that can contain a 2 year old and ideally not super expensive (I recall hearing about 1 or 2 but I think they were over $200). TIA!