Yes:
You can get plastic or Al rings to go outside the chainrings.
Full-length chainguards to protect you from the top of the chain, (these can work with triple chainring systems as found on European city bikes.)
Fully enclosed chaincases, these work with singlespeed and hub gear systems.

Finding a chainguard in the US may be a problem. They can be had from some UK mail order houses, but you are better off with a continental euro place.
I use trouser clips to keep my trousers (US pants) clean.