At the risk of stepping onto the turf of the sports uniform blog, I wanted to comment on how a couple of teams' softball helmets are designed to imitate football helmets.
Traditional softball (and baseball) hats put the team abbreviation or logo at the front, above the bill. As shown in the montage below, however, the University of Wisconsin softball helmets adopt the football style of putting the "W" on the side, with a stripe from front to back, over the top.
Meanwhile, Oregon State's softball helmet bears a resemblance to the Michigan football helmet's design, with the winged pattern in front and stripes going toward the back.
I don't really know what to make of this, other than to say that athletic directors and softball coaches and outfitters apparently feel free to experiment a little with their uniforms. Softball is not the only place this happens, however. The Michigan hockey team also borrows from the football helmet design.
Update: I posted a message on the discussion board at Ultimate College Softball, asking if anyone knew of additional teams that had football-like or other unconventional helmet designs. A participant with the moniker "Pudge" listed the following: "Oregon and the two big O's on the side. Florida State with the spears on the side." Indeed, if you go to these teams' official sites (Oregon, in the player montage at the top of the page; Florida State), you can see these examples.