Hi Phoread,
I spent a fair bit of time checking out various packages, and found a couple I liked. (NB: I'm not getting kickbacks for this)
I'm using MindManager Pro X5 myself, and successfully used the "presentation mode" to deliver a uni seminar a few weeks back. (Goodbye Powerpoint & linear presentations forever!) As good as the program is, I'm aware of a few shortcomings with the software - hopefully the new version addresses these.
I note that Tony Buzan has put his approval on another Mindmapping program, the name of which escapes me for the moment (just search for "mind mapping software" - you'll find it quickly enough). Without having tried the program, and judging only from the screenshots, it seems to incorporate pictures & colours into the mindmaps better than MindManager, but I'll have to have a play for myself to really find out.
There's a freeware bit of MM software called FreeMind, which is great for what it is. Very limited ability to change fonts/colours/incorporate pictures, and no ability for the user to choose where branches go, but it still does some handy things that even the commercial software doesn't. On balance, though, I'm inclined to prefer MindManager.
I'm soon to get a copy of PersonalBrain, which is like an enormous mindmap, only in 3D... not much good for presentations (structure would be too confusing), but I reckon it'll be great for collecting a storehouse of info, and especially useful for syntopic reading.
Cheers,
Ken.