My ten year old is playing with them more than ever.

PP Here: We have a separate flip top container for DH's legos. His are stored separately from the kids. He only allows them to play with them when's he's observing them the rest of the time they play together with the kids legos using the Container store bin and lay n go.

We ended up getting a rolling multi layer container from Container store to store our legos - you can separate each of the 3 bins and their are handles to carry them. The bottom one is larger, top is smaller. I collect as best as possible each kit, the instructions and the pieces into a zip lock bag and put them into the bin. http://www.containerstore.com/shop/toyStorage/boxesCases?productId=10000647&N=80471

I like that it can be wheeled and moved to where ever they want to play (this includes 43 year old DH). I also got a Large Lay n go http://www.amazon.com/gp/product/B007BO5OAY/ref=oh_details_o04_s00_i00

This allows them to have a kit out they are working on, move it around and not worry about losing any pieces. Recently they worked on one with 1000 pieces that took several weeks to finish - the lay n go meant I didn't have step on pieces, hear them complain they were missing something and they could move around the house and work on it where ever they wanted.

OP here - thanks for the helpful responses.
To the adults who still play with legos, do you have a designated area of your home where you keep your legos, or do you just hog your childrens' sets? Asked as a parent who enjoys magnatiles more than her kids.

DW is the 37. She's bought and assembled all of the Harry Potter Lego sets and is now starting to work on the Lord of the Rings collection, so as far as outgrowing legos, in her case the answer is never (lols)

My 12 and 7 year old boys still play with them.

I am a 42yo woman and I still play with Legos whenever they're available.

My husband is 45, and we still do legos every Christmas day.

My brother's roommate is 40 and still has all kinds of sets. I have to agree with the pp the other toys are one's they are more likely to grow out of. One of my friends got one of those rolling drawer like things with shallow drawers and she said that worked pretty well.

There are grown men who buy legos and play with them

What I did was bought one of those giant double wide, shallow, under the bed plastic sweater bins. It holds everything, slides out of sight and is easy to access. The kids pull it out when they want to play and slide it back when they are done.

Since it is shallow and clear, they don't pull as many legos out at a time as they did with the deeper storage bins.

FYI, I have boys just a little older than yours, and what I ended up doing was to box up or get rid of just about every other toy but the legos. That helped a ton with getting rid of the mess. The only other indoor toys they play with now and then are their Bakugans and Transformers, but those mostly stay put away in bins. Legos are the only toys they play with daily.

I catch my husband playing with our sons' legos when he watches TV. You might be in for a long ride

I don't really know how long kids play with Legos. I know that I would still play with them if I had time and I'm 34. But the nice thing about Trofast is that you can just put shelves in, instead of the bins, and you could use the shelves for books or paper or art supplies, or just whatever. I think they're pretty versatile. And if you decide you don't want them or they don't work any more, they would be an easy sell on Craigslist. I'm pretty fond of our Trofast, but my kid is only 5.

My 11 year old nephew still plays with Legos.

My 11 and 9 year-olds still play with LEGOs constantly.

I have 6 and 8 yr old boys and a very disorganized playroom which I want to get under control. My first order of business is to do something with all of the legos. I like the ikea trofast system for corralling legos, but I am concerned that the kids will only play with legos another year and then I will have a very specific storage system which I may not find practical use for with older kids. How long did your kiddos play with legos?