Just as long as you have it preload with the right amount of money, funding in it, you can. I too have switch over to the reloadable debit cards for a while now and is generally very pleased with using it in various important ways-mostly online and over the phone.
You might be pleasantly surprised that it seems to provide an additional layer of protection. Possible scammers might be put off by the cards not carrying a large amount of money just sitting there for the taking like regular credit and debit cards do. They only have what you put into it!