I mean there's a lot of ways you could do this right now with the current tools depending on how complex your needs are. If you just need a simple "there are 3 levels of flying" sort of thing, you could tint the tokens to different colors and all the ones that are the same color are on the same level. You could also use the colored markers for a similar effect. If you need to know the exact height, as Eric said you could use one of the bubbles for that. If those are all taken or you always want to see the height, put it in the token's name and show the nameplate. Or you could even easily use the text tool, add a new text to the map, put it where you want it by the token, then group the token and text together so that they move relative to each other -- then just use Alt+Click to select either/or if you just need to move one of them or edit them. I think one of the things that we've tried to do with Roll20 is give you some generic tools that you can use for all sorts of purposes. We really want to try and avoid getting into case-specific tools whenever possible. That said, if a ton of people are using this and there's a better way to do it we'll certainly consider it -- but first maybe try and get creative with what's there and see if that works...
