Men's jerseys will fit if you're neither too chesty or too hippy and you can live with a little room around the waist....basically if you're not too curvy. Think straight cut vs. form fit. Also, they are almost always longer than women's--both because they are men's cut and because men's designs tend to be of a longer design.

Me? I wear men's jerseys when I find one I like, but then when not biking I spend most of my time in baggy T-shirts or sweatshirts. After that, almost anything feels snug. For me, it is the extra length I love.