deciding on lenses

recently i decided that i need to add to my lens collection to get some shots that i want. I was looking at either the Canon 70-200 F4 or the Canon 100 F2.8 Macro. I am debating the usefulness of each lens and was thinking that maybe the F4 will be limiting and i should just get the 100 macro and use it also as a 100mm prime telephoto lens. Or should i just save a little bit and get the Sigma 70-200 2.8? Though i have really been missing macro since getting rid of my S2IS. anyone have any helping input?

I have both, and if I had to do without one, it would be the 100 macro. Both outstanding lenses, but for me, the 70-200 is just too good. I haven't found the f4 to be limiting (yet). Compared to the f2.8 70-200 offerings, the f4 is a featherweight. Something that I took into consideration before buying. Like I said, both are excellant lenses, I just find the 70-200 a little more versatile.