Do I need to buy Motion?

with Motion, you can create your very own Generator/Effect/Title plug-in, with a convenient Drop-Zone, and preformatted Text areas and sleek animation and and and...

But for quick'n dirty you can use any PaintApp, here Pixelmator:

create the chart, make a 'hole' into it and save it a s png (to keep ransparencies)

gives: ...

… when you drag upon your video ...

Just to add my $0.02 to Karsten's great advice: this can now also be achieved within FCP X itself by using the new masking capabilities, and the save presets.

I think you can get pretty decent results with FCP X alone. As always, Motion provides a LOT more customization possibilities, but that also comes with a steeper learning curve, and the sheer amount of parameters available can be daunting.

I just did a little experiment and with the Draw Mask or Shape Mask in FCP X it is trivial to make a picture oval; using the transform parameters one can place it anywhere in the frame; and with a few keyframes it can be made to come in from the top or the side if you want; also you can add a drop shadow or whatever you like. Once you get it to work the way you want, click the "Save Efffects Preset" button in the inspector, choose a category and a name, and it will sit there for you to use whenever you want it. Really powerful, really easy. Amazing stuff.

About the "spin": you can add two rotation keyframes to the above and make an image spin, in addition to move and scale, in FCP X.

(In Motion, one would probably use a parameter behavior instead).