Huh, it worked for ö, but א gave me:

    ! Undefined control sequence.
    \u-default-1488 #1->\hebalef

And the Japanese example above gave me:

    Package ucs Error: Unknown Unicode character 12371 = U+3053

Either way, there's not much of a point in using LaTeX when XeLaTeX is available, save for intercompatibility. So until sites like this one start moving to XeTeX/XeLaTeX, we'll still often be stuck without (true) Unicode.