Of course. If you're familiar with using the Terminal:
Type the following (including a space at the end) into the Terminal:
chflags hidden
Now drag the folder you want to make invisible into the Terminal window (or manually type the path in the Terminal) and hit Enter.
To view Invisible files and folders, simply hit Command+Shift+. (period key) in the Finder or an Open/Save dialog box.
To unhide the folder, run the same commands as you did to hide the folder, only change chflags hidden to chflags nohidden