I just ordered a pair of snazzy black rings from Rogue Fitness yesterday, here's hoping they reach me in the mail soon! I've read reviews on the CF message board as to just how awesome these rings are - hardy, grippable surface that holds chalk well (very important to a sweaty-palmed person like me), and easy to rig and take down. I'll post a review and pics of the Rogue rings once I get them and have a chance to try them out, so check back for my opinions!
It's been a significant while since I've done any form of ring work and I'm looking forward to working on more gymnastic skills and ring complexes once I get them. In my opinion, gymnastic rings are quite possibly one of the best fitness tools you can have around, for a variety of reasons. They're portable (much more portable than a kettlebell, which is something I can testify to after having transported my 16 kg MuscleDriver bell back to Singapore as one of my checked-in luggage pieces - as you can imagine, I opened my bag back home to find a leaflet politely informing me that TSA had inspected my bag), you can pretty much rig them up anywhere - loop the webbing over a sturdy tree branch, a high beam, a pullup bar, whatever - you can perform a myriad of exercises on them - dips, pullups, muscle-ups, a million variations of pushups, skin-the-cats, front levers, gymnastic progressions if you're so inclined, static holds, handstands... the list is endless. The adjustable webbing also means that you can pretty much scale the workouts as necessary - shorter webbing provides more stability, hanging the rings lower enables you to do jumping ring dips or negatives if you can't do them unassisted yet, and inclined ring rows are way superior to inclined bar rows if you're looking to build up muscular strength in your back and arms to be able to do pullups.
Well, so that pretty much tells you that I think rings are the shit! :D
A couple links to rings/ring training:
Rogue Fitness's Rogue Rings. I believe you can also order Powermax and Elite Rings (discussed below) off the Rogue catalog.
Tyler Hass's (maker of Elite Rings - a great product, I've used them before) RingTraining site. You can buy his Elite Rings here, which I believe comes with a guide to ring exercises that will keep you pretty occupied for a couple years, and there's articles on his site that also discuss rings and how you can use them, in far better detail than I can.
Powermax Rings, sold by Gill Athletics. I wasn't so impressed with the texture/feel of these rings because I found them quite slippery and heavy, but they're a good option nonetheless.
CrossFit forum thread on homemade rings (read it, you'll be impressed at the quality of some of these self-constructed rings!).
Getting started on ring training - courtesy of gubernatrix. A great foundational article on some exercises you can try out on rings!