Claudia,
You may if you do a lot of traveling want to invest the time to try to get a US Visa.
The reason I say this is due to the fact that many people I know are issued with 10 yr multiple entry visas by the US.
Canada is much easier to get a visa, but usually restricts it to a single entry!
It's a shame you need a visa, but coming from a country that has seen a lot of abuse with our refugee system I hope you can understand the reasons behind it.
Right now we are battling a lot of illegals from Asia, India, and Eastern Europe. 2 yrs ago a bunch of Czech Gypsies came (after a false T.V. Report) to Toronto and demanded their free homes, cars and money. After 1-2 weeks (and not receiving any free hand outs) they decided things wern't so bad back home and decided to go back!