Before I get too deep, lemme clarify: dude does walk, and he walks frequently, but he tires a little more easily than many children and the AFOs he wears to help bring his heels to the ground aren't what you would describe as comfortable. This combined with the fact that he and I walk a lot during the day (like to 75% of the places we go) is what set me on this quest, and dude weighs around 32 lbs right now.
It turns out there are a LOT of carriers for preschoolers — and they run up and down the budget scale. Here are a few that I found:
The Boba Classic is made by the same folks, and the main difference I can spot is that the Classic can be used from the time your baby hits 7 lbs until he or she is 45 — which is generally a long time. It comes with foot straps for when your kid's feet need a break. This is actually the carrier we ended up going with — the foot straps help keep our son's feet at a 90 degree angle AND I found the carrier itself for $65 on eBay. WIN.
The Beco Baby Gemini Carrier is a 4-in-1 option: you can wear a baby facing in, facing out, on your back, or on your hip. As your child gets older the way you wear him or her will change, and the Gemini can accommodate a kid up to 35 lbs.
Last on the list is the Beco Butterfly, which is similar to the Gemini but only allows for front and back carry. The customer reviews on Amazon are all stellar, and the carrier holds kids between 7 and 45 lbs.
Those are my favorites — what options are fellow toddler-and-preschooler wearing parents using?