No problem

Thanks Kurt! I'll use that if I need it, I just figured out I didn't need it.. Thanks anyways!

Well I guess use a scoreboard.. for the scoreboard /scoreboard objectives add Ground dummy then make a redstone block clock then put a command block that has a command /execute @e[type=FallingSand] ~ ~ ~ detect ~ ~-0.2 ~ air 0 scoreboard players set @e[type=FallingSand,r=1] Ground 2 another command block with command /scoreboard players remove @e[type=FallingSand,score_Ground_min=1] Ground 1 another one with /kill @e[type=FallingSand,score_Ground=0].

/summon FallingSand ~ ~1 ~ {Block:gravel,Time:0,FallHurtMax:100}
or

/summon FallingSand ~ ~1 ~ {CustomName:"Test",CustomNameVisible:1,Block:torch,Time:1,Riding:{id:"FallingSand",CustomName:"Test",CustomNameVisible:1,Block:gravel,Time:0,FallHurtMax:100}}

Sorry then, that's how i have always done it!
Sometimes you have to be inefficient with command blocks...
look at some of sethblings map! i could have made them with like 100 command blocks less but they are still some of the best...

Well, yeah thats the easy way... I was saying all blocks. I could've easily done like 10 cmdblks aligned, but its very inefficient...

Hello good sir!
The answer to your question is no!
well kind of!
you can actually achieve this using the /execute command!

if you set up a red stone block clock!
then have this command running twenty times a second it should work!

/execute @e[type=FallingSand] ~ ~ ~ detect ~ ~-1 ~ stone 0 /kill @e[r=0,type=FallingSand,c=1]

[NOTE:You will need to have a different command for each material you want to kill the sand! just change the "stone 0" to "<BlockName> <DataValue>]

-snip-