I did tinker around with MystCraft in creative mode just to figure it out (while watching a handful of YouTube vids). VERY cool mod for sure.
What I wasn't able to figure out is whether or not you could link to areas in the same "age" (or the same world). Sitting here at work I thought of something that might work, maybe you can tell me: Say I've got two points I want to link together, points A and B. If I create a linking book at each point, but put the books at the opposite point (on a stand), would they link together? If so, that would certainly be an alternative - and technically, a much cooler alternative. Just not quite as simple.
As for the crystal portals, I did watch a video about it, but didn't have time to test it out. Again, are those able to be linked within the same age? I did find some information about "Intra-Age" linking in a MystCraft wiki (http://binarymage.com/wiki/doku.php?id=ages:linking) that states:
"
Neither Linking Books nor Descriptive Books allow players to link to a location in the same age they currently occupy, without a
Link Modifier
. If you wish to use a non-Intra Age linkbook to travel to a place within the same Age, you must first link to another Age, then back to the first.
"
Obviously, I hope that we all end up with the resources to have a link modifier, but we won't have it from the start (unless I prebuild some for everyone... that's a possibility). Sorry, I'm starting to ramble now. I'll wrap it up.
Oh, and I also saw in that howto thread that MultiVerse Portals were working, but another note that said most MultiVerse stuff wasn't working - so I didn't even try that one.