I've been randomly hacking things in my head for Cortex plus and it's produced a few usable widgets that I figured I'd share.
Cracking Dice - This is a pretty simple concept, but it struck me as something that might streamline any dice distribution system, especially in the case of something open ended, like super powers. The idea is simple: any die may be "cracked" into two dice of on step lower, so a D12 might become 2d10, which in turn might become 1d10 and 2d8, or 1d10, 1d8 and 2d6. It's a good way to get width out of height.
Now, applying this mechanically has a few possibilities. I wouldn't suggest applying it to actual rolls, though I suppose you could do it. What I was specifically thinking was that you could just hand someone a d12 and let them use that "budget" to buy powers. If they just want Invulnerability d12" then that's fine, or they could crack it and get "Superstrength d10, Invulnerability d10" and so on (Obviously, this implies an entire powers system but that's another discussion.) It could even support the spontaneous purchase of new powers if deemed necessary, by cracking dice in play.
Five Step - So, the simple fact is that Cortex plus maps very tidily to a 5 step system (d4/d6/d8/d10/d12 and 1,2,3,4 and 5 respectively). This is noteworthy because there area lot of five step systems out there, most notably the various World of Darkness games. Certainly there would need to be a little tweaking on the powers (# of successes could be calculated by the number of winning sets you can built, frex) but I'd be really curious to see about running something like Mage as a straight up conversion (well, maybe not Mage. Dave Chalker already has a fantastic Mage hack for leverage. But you get the idea).
Best Friends - Carl Rigney had the most brilliant idea which I am taking and runningn with. Basically, you can take the Best Friends character creation system and apply it to Cortex+.
For the unfamiliar, best Friends has a wonderful chargen mechanic based around a core set of stats like strong, tough, smart and so on. The list isn't important, and I change it to suit. What's important is that in chargen you go through the list of stats and say who you hate because they'r better than you. That is, you have a list like "I hate Lisa because she's stronger than me. I hate Tina because she's richer than me" and so on. Everyone's stat is the number of people who hate them.
As noted previously, it's easy to turn small number numerical steps into dice, so that Cortex+ conversion is easy. But what intrigues me most is that _other_ thing I like to hybridize with Best Friends: Amber. It calls for a slight change in stats (Including "Because dad likes him better") but that's easy. But better yet, If you do this for the core stats and something else for the roles, then stats can be done _secretly_ and kept obscured. That is to say, Players write down their hates in secret, and the GM uses that to hand out stats. No one knows who is really the best, and Cortex+ very naturally supports "faking down" your high stats if you want to - just use a smaller die. Simple as that.
Anyway, this is what rattles in my head when I don't have a good audiobook. Figured I'd share.