In search of good mind-mapping software

So I recently started to create mind maps to summarize studies and come up with new ideas. It's better to start a map on paper than to use a computer program, granted. But then, after the initial session is over, it would be good to make a digital version of it to be consulted and edited later. A mind-mapping tool is thus a good idea.

I tried some programs on this list. FreeMind is one of the best free software tools for mind mapping, but it still has lots of usability problems, and it runs on the JVM, which means slow startup and eats-lots-of-memory. Mind42.com is interesting exactly because it is a web application, no need to install anything, available anywhere, etc. But I couldn't try it; after signing up for a free account more than 24 hours ago, I still haven't received the confirmation email, so I can't login. I guess I won't bother trying to register again.

But it gets worse: both of them doesn't seem to support links between nodes in different parts of the tree (cross-links). Does everyone that does mind maps manage to categorize everything hierarchically? To me, in any non-trivial map there'll be lots of relations which are not hierarchical in nature, and I think that not allowing these cross links is a serious limitation. Maybe I should consider creating semantic networks, but there doesn't seem to be tools for that.