Dongle without time restrictions???

[cemeterybird]

Hi - If anyone could give a computer illiterate the benefit of their knowledge please? I purchased a small netbook, primarily to take on holidays with me, to just generally keep in touch with people but for instance, I stayed in a B & B recently and although picking up plenty of signals, they were all security abled, so I wasn't able to connect. 'A Dongle is what you need' says various friends and colleagues and I have been trying to do my homework on these small but complicated items!!
I think, what I want, I cannot get but if you more experienced could confirm this for me or tell me otherwise, I would be very grateful: I don't want a dongle with time restrictions because of only needing on rare holidays - I want one I could use, next week say, then not for another 3 months. From the multitude of different offers and information out there, I cannot find one that seems to offer this.
Any help appreciated...... many thanks. Janet