If you don't already know what an RZX file is, i'll attempt to enlighten you. Quickly.
An .RZX file is basically a recording of what's going on on a Spectrum. It's used to record game progress, which is good for competitions and things of that ilk.
Anyway, a new site is up, like the TZX Vault, but for these recording files. It's called the RZX-Archive. Not much there at present, but keep an eye out, and record your own.
Oh, while we're here a couple ideas for domain-names based on a once-good Sci-Fi series: RZX-Files and TZX-Files. Oh, and don't forget ZX-Files. I'd get them myself, but I already have more domains than I know what to do with. I'm happy to do some hosting, tho'.