An advice from personal experience - stay away from Lebara which can charge you 6.20 CHF for just  receiving a 10 second call!

I'm not aware of data only providers, though I think that Orange offers unlimited data package for 30CHF,

Stay away from Yallo, supposedly very cheap and it ended up costing me more!

I would charge my phone with 50 CHF and 5 days later it was asking me to recharge again!!! (the crazy thing it that I only use my phone for texting!)

It comes up it had some hidden fees and some other crap so I ended up switching to a regular Swisscom one.

thanks a lot. i was thinking about going with orange.  any experience with contract service? i'm primarily using my mobile for internet connectivity.

cheers.

Unlimited data for 30CHF?? Are you sure? As far as I know there is no provider who will offer you unlimited data.

I think it is probable that Orange offers unlimited data package for 30 CHF (likely if you sign a long-term contract, though I'm not sure), since yesterday I went to a Sunrise shop and what they told me was that I get unlimited data package for 19 CHF only, if I sign a 1 year agreement with them.

So, why Orange can't offer the same service for 30 CHF?

Because these guys will say something like unlimited so long as its less than certain amount per month or pay day.

Unlimited means no restrictions whatsoever. So its not unlimited.

I think you're are partially right. I've just checked here

http://www1.sunrise.ch/Surfer-sur-son-mobile-cbmtXAqFI.pN4AAAEkBWZQzDCf-Sunrise-Residential-Site-WFS-fr_CH-CHF.html

and it says that you get unlimited access for 19 chf per month. After reaching 2GB of traffic usage, they slow down your connection to 128kbs, which I think is still OK. In other words, you still have unlimited access to the internet at the speed of 128kbs. The difference is only in the speed, but not the access to the web.