This took me some time to figure out. It's a shell command to extract the URL from an svn info command. Run this (or put it in .bash_profile):
alias svnurl="svn info | egrep '^URL: (.*)' | sed s/URL\:\ //"
Then you can do things like svn ls $(svnurl) or svn log $(svnurl) to run commands on the remote repository. I expect this'll save me a bunch of time in the future.
And this is another one I've used for a while, to view changes in a working copy, especially useful when there are externals that output text even when there are no changes:
alias svnnew='svn st | grep -e "^[!M?~ACDR ]"'