Portal

I freaking LOVE Portal. We simply must have this in SL lol. Ya ya ya..logistical nightmare totally impossible. We can't create portals in Sl. .. But. Creating a whole build of puzzles to be used with movement enhancers in a no fly zone, and taking on damage for collisions with certain obstacles instead of bullets...maybe even packing some of the enhancers into a portal gun ("Aperture Science Handheld Portal Device",
whaddya think?
I'm just in love with the companion cube, i admit it. I was given a FP one inworld that looks *exactly* like it (sculpted). IM me for a free one to go scortch.

Portal gun that actually works found on slexchange last night. Search for it, it's fun.
Have found several cubes for sale that pale in comparison to the freebie i was passed...still handing those out too btw

There are at least two portal guns around that fire "working" portals - in the sense that when you walk into one, provided you are carrying the gun, you are teleported (via the "hyperdash", aka "impulse boost", aka "bungee-whack" method to the other portal. (It's got to be in the same sim, of course.)

Of course, you can't see through the portals, and the portals can't turn you around. It may or may not be possible to "fling" through them though (they could save your velocity on impact and then push you at the other end, although I'm not sure if you can get a good velocity on impact).

You could maybe do some of the simpler puzzles from Portal with SL, but most of the later puzzles in that game depend on flinging, connecting environment, or being halfway through a portal at the appropriate moment.

theres a pink bunny in furnation that is building on portal themed objects and various talking sculpted prim companion cubes around there.
He is using some advanced invisprim tricks to hide a room from all sides but one, and see right trough the room from all other sides. that can look like a portal, good enough for screenshots.

Portals in SL are barely functional. They work by pushing you using llPushObject(which is turned off in nearly every region). These "pushes" are easily disrupted and can often be miscalculated leading you to be orbited.