Fisher Price’s website has some awesome computer games for younglings.
I love the JumpStart series, too. It’s an older game (Microsoft XP era), but JumpStart Toddlers is great, because every button they touch does something, so they learn really quickly the cause/effect relationship of the keyboard and the mouse. After that is Jumpstart Preschool, Kindergarten… my son is on the 2nd Grade disc now. It’s cool because it tracks his progress in different skills (spelling, reading comprehension, math, whatever) and gives me a progress report.
One fun thing might be to search Craigslist for someone giving away an older model computer for cheap, and getting that specifically for him. If you grab a few kids’ CDRom games (and oh, boy could I give you a list) you wouldn’t have to hook it up to the internet, and it’s really easy to neuter it so they can play freely, but can’t get into system folders until they’re about 3½ years old. Honestly, he figured that out sooner than I expected.
My uncle tells me I had DOS cracked at four and a half, so I’m sure your little one will be coding in no time.