i have an image i want to place on a coffee cup image.

for it to look good, i need it to "curve" around 3d shape of the illustrator vectors. nothing is actually 3d.

can anyone help me, please?

i've attached an image to clarify

why don't you use the 3d tools built into illustrator, there you can create a clinider and map an art over it...

how?

In Illustrator CS, use the "Warp" tools here: Effect/Warp/Arch/Bend @ -25% to start. Fit to taste with the preview activated so you can see your changes in real time.

Let us know if this helps.