There are a lot of ways of getting free internet through USB dongle pero I always use Globe kasi no maintenance sa balance kahit 0 magcoconnect talaga sya sa dashboard nya. Smart is also ok but the problem with it is you need to have at 2 pesos load which most likely will only last for a couple of days and para saken, mabagal ang Smart kahit sa legal na paraan kasi you'll only get decent speed pag madaling araw. Once it hits 7 am, the speed will go down. Sun naman I haven't bothered to connect na kasi kahit may 2 peso load ka, ayaw magconnect sa dashboard, mapa-regular or broadband sim which I both owned.
Sa mga gusto magpaunlock ng USB modem nila, there are free programs out there that will serve its purpose. I have 2 dongles, 1 from smartbro and other for globe tattoo and I've successfully unlocked both. Just use pareng google.