Another way about - instead of prepending the executable name with "./" you
could also add current directory, "." to the PATH
PATH=.:$PATH
There is a reason why this normally isn't so - security:
Not having "." in the path means that nobody can trick you into running
his replacement "ls" (or cp, mv, ...) that he has just lying around in the
current directory.
This rule has been reinforced by student pranks on machines used in labs
and is by now so ingrained that no normal *nix user would even think of
adding "." to the path.