I haven't written for a while about terrain building, mostly because I have not built much aside from the odd piece for my modular dungeon. But, I have been considering getting back into making some things, and in a very timely manner happened to spot these fellows in the "Spot" section of Target.
You don't see too many just generic Legos anymore--instead it is all building kits and the like. Legos, or complete knock-offs like these, are great for creating 90-degree angle forms for assembling Hirst Arts blocks or other things.
Let's be clear--they are NOT Legos. They are flimsy and soft. But they are also only a dollar a bag, and for what I will be using them are perfect.