There is no big deal about the fact that we worship shiva's linga. According to the hindu mythology, seven sages (saptarishi) cursed him for a crime which he did not commit and that's why his genital organ had to come off. The seven sage wives (sapta rishi patni) used to worship lord Shiva immensely, but their husbands took it in other ways. If lord Shiva's hand had come off due to curse, we would still have worshipped him equally. Its not the thing that we worship god's penis, but the fact is we worship him that is why we worship everything associated with him. It is interesting to see that while Hindu religion have given due respect to WOMANHOOD, our culture have failed to do so. Interesting also is to note all the big wars in our mythology have women associated as main reasons behind them. Sita, Suparnakha and Draupadi all were women and unfortunately all of them have contributed for the initiation of the wars in their respective period. Something to think about.