I'm new to the whole universal remote thing, but am fed up with fumbling a dozen remotes. I've read about remotes that can read IR signals from other remotes and learn those signals -- can this be done with RF signals as well?
No, but I think I read a post from someone who built his own RF to RF translator.
As for what IR remote to recommend, it depends on what you are looking for and how much you are willing to spend. I prefer remotes on the more expensive side (200$+), but there are good learning remotes for under 30$.
You can read the reviews (a lot of detail and anything you would want to know about them.
My three favorite categories (used to be remotes, but if something is good it expands to a family of similar remotes)
Pronto: Uses a Touchscreen prices for all 12 models and 4 manufacturers (Philips, Marantz, Yamaha, Onkyo) range from 220$ to 1300$. It is a bit complicated to setup, but easily becomes a hobby. It is the most customizable of all remotes, you can have channel macros with the actual channel icon (push the ABC icon to change to ABC). Can be setup so that even the most technophobe can use your system
Harmony: (two models) for basic setup it is extremely easy to setup (tell it what you have, how it is connected, what channel you have.... and it does the rest). Can get a bit complicated to setup if you want to go into advanced features, but the Harmony support is great at helping with that. You can also download the TV listings (US & Canada) and instead of picking a channel you pick a show.
HTM: (MX-500, MX-700) if you like push buttons and lots of them these are the best remotes