So i played millennium army's mini game map last night and one of the games was a race. In it the units seemed to slow down and then speed up. I know that if you constantly move a unit to a location that is being centered on another unit, that unit will slow down drastically. but i've never seen a unit's movement speed actually increase. Anybody know how to do this and if it can be applied on a global scale (ie have templars move faster)...i doubt it but it would be neato.

There's several methods, but nothing matches exactly what you're looking for:
- speed upgrades, stays permanently once it comes into effect and works only for a few units
- increase map speed by placing a P15 scarab (?) as the first unit, units will always be fast but can be slowed down with the 3rd method:
- slow other units down by constantly moving burrowed units under it, not really a speed increase but makes a certain unit appear faster. Can be switched off and on at will
- constantly move a unit to a faster unit, choppy movement and can't be targeted

It's a Map Revealer, I believe, not a Scarab.

Depends on what speed you want

However, the way MA did it is by simply starting the units slowed down using the constant moving trick, they never actually go faster than their maximum speed, he just slows them down less, by moving the unit for less cycles to slow them down.

I was thinking of making a Mario Kart map based on this concept, but I don't know how effective it would really be.

make a Mario Kart map for 1.13a or whenever EUD actions were still around and edit the top speed of the unit. (note this is no longer possible in the current patch).

Also, you can do this for any unit with artmoney in the current patch, and it's absolutely hilarious to see units blinking around.

I've never liked the burrowed unit, as it slows diagonal travel much more than horizontal or vertical travel.

does this art money change require users to dl content or is it usable on bnet? also will bnet updates ruin the changes...i'd imagine so

Art Money views and edits memory. For example, you can find a units speed, change the number, and it will change the speed in starcraft for that unit, however it will drop every other person so it's only single player.

Map revealer only increases unit animation, scarab and interceptor increase game speed.

Can you explain why, or is it way too complicated to explain?

I would think it has something to do with how fast a scarab and interceptor go because they're probably the fastest units in the game.

I doubt it. Map revealers don't move, and nukes are the fastest unit in the game.