Well i must start off by saying...I ABSOLUTELY LOVE THESE!
They really do taste exactly like the soda which i was extremely surprised about! They make your lips feel very soft and dont dry out your lips if you apply it too much like some other lip balms/ glosses do. They are very cheap - i got mine from claire's accessories some time ago now, and even though they are small they last quite a long time.
Even though they do 'taste' nice; I find that sometimes it gets a bit too overpowering especially in the mornings you don't really want a mouth full of 7-up! However they are great sized and fit in your bag or pocket very easily. They are quite unique and many people have asked and enquired about them when ever i have used them whilst out with friends etc.
They even makes your lips look soft and quite shiney