I remember, without too many details, that when a womens' minyan started in Chicago many years ago, they met with fierce opposition by some of the local rabbis. One of the issues was that even if most of the time such a minyan is not problematic, there are times where it is inappropriate, such as women reading the megilla if I remember correctly, and therefore it is better such a minyan not be held at all. So that in those problematic situations we don't end up with women doing something they should not be doing.

Rav Ovadia Yosef, in his weekly motzei shabbos shiur, spoke about women reading the megilla, and about women writing megillas. It is a surprising psak, considering how liberal it is, and it seems out of charachter. Regardless, it is interesting.

If you have the patience to listen to the shiur, I recommend it. Rav Ovadia throws in some anecdotes and it is an interesting shiur. It is difficult to understand, as Rav Ovadia always is, but you can make out most of it if you listen carefully. I consider it important to listen to, because the source where I first saw it menioned, Haaretz, is not reliable in quoting properly (out of context, etc) halachic commentary, and when possible it is best to get it from the source.

Rav Ovadia talks about the women reading the megilla at about 10 minutes in to the shiur, and about writing the megilla about 26 minutes in.

Rav Ovadia stresses that while a woman could lein from the megilla, it is preferable that she not. However, in a situation where there is no man available who can read, such as maybe in a small settlement, a woman can definitely read and be motzi others, including men, their obligation. Rav Ovadia says they can read because they have the same obligation as men, and they were part of the miracle.

What about listening to the voice of women? Reading, even with the cantillations, is not comparable to singing and is ok.

About writing the megilla, Rav Ovadia says because they can read they can also write it. It is clear that there is no problem with them writing a megilla. If they have parnassa problems, they should write megillas, Rav Ovadia says! A different problem is who would buy it...

Rav Ovadia relates that it used to be common in some places, such as in Yemen, for women to write tanachs and megillas. He relates an anecdote of a tanach written by a woman - he says she signed at the bottom a note that she wrote the megilla and apologizes for any mistakes. She says she wrote it while she was pregnant, and was having contractions at the time, so she might have made some mistakes.

Again, as always, do not rely on anything quoted here for an actual halachic decision. Contact your own rabbi if you have any questions.

MOI wrote about it earlier, and the comments are sure to be diverse on this topic...