Motorola Triumph "low on space"?

[Miranda]

So my Motorola Triumph almost constantly has that little
"Low on Space"
"Phone Storage is getting low" notification and the "Text message memory full" one, too.

I seriously only have TWO apps
Twitter and Kik.

and right now I have a total of 115 text messages.

Can someone tell me how to get rid of this?? It's REALLY irritating!