My experience with Onesimcard.

[rfranzq]

Originally Posted by Sophia

...and then I traded the Celtrek sim for the OneSimCard because I had nothing to lose anyway

Best $0.0 you ever spent! [Loonie or greenback]

And here is some good news of the last month or so:

New Toll Free access number for customers in the U.S. or Canada to retrieve voicemail for free: 1-866-703-4770.

And here is the bad news:

First you need to call to the voicemail from your OneSimCard phone and set up a password.

At least in Canada you will not spend half your free balance setting up voicemail. I just had an opportunity to send the SIM with someone on a trip and asked that they set up voicemail on it.
And you can always use SMS.