From all the info I've gathered (and
trust me, I've dug into this a lot) Virgin Mobile doesn't support Emoji to other carriers. At least through SMS. In Handcent, there's an option to send emoji via MMS, but you will be able to send and not receive. When you receive it, you will get the random question marks and spaced out letters. The weird part about that is that I know Sprint phones are able to send it and receive and other carriers are too.
Now with Instagram, I think you are talking about "seeing" emoji in other third party social media apps. Now, that's a problem on Android itself. We don't have the necessary files (I'm sure if Google/CyanogenMod wanted to implement it, they probably could) to see emoji in color. BUT, the MIUI gb ROM we have available does have that option, and it's the only ROM I've ever used that's had it. If you don't mind seeing emoji in black/white, you can follow the instructions on
this thread