I doubt you'll find a good free hosting for a 30 Mb file (they usually don't offer more than 25 megs for free), without encountering any inconveniences. I don't know how much space these free hosting services can provide and how much allowed bandwidth each day.
You can try these services, but I haven't tried them myself, so I can't say how much reliable they are:
www.da.ru
www.0catch.com
www.virtue.nu
www.50megs.com
www.topcities.com