yes - i have!

it was a full size sim card from lime
i bought a micro sim card cutter online before the trip ($5 from amazon)
also - in the APN settings you have to label APN as "ppinternet" -no quotes..

i activated a weeks service right at the lime store - then cut the sim into a micro -then inserted in the ipad - it didnt work! so the lime clerk called customer service - which instructed us to label the APN as ppinternet.. bango - i was online.. worked like a charm..

this was back in February, when micro sims were less common - lime might have micro sims now as they do sell iphones now..