But it seems things have changed.
My contract with Orange is up this month, and I have already arranged to port my number to Coop Mobile (which is not really porting it because Coop uses Orange's network).
So, in case there are other people that would like to use some data from their phone but not sign a contract with a phone company, I will share the results of my thorough research of the Swiss prepaid mobile market with you.
I ended up with two interesting offers. 1. The first one is Coop Mobile , which I chose for myself.
Ignoring the rest of the rates, which is not the scope of this thread, it gives the option to buy a 100 MB bundle each month for 9.90 francs. The first three months are offered for free.
My flatmate was very happy to discover he can use VoIP in his smartphone with his Coop Mobile SIM card (he didn't have to wait for his contract to expire).
2. The second option is Talk-Talk .
It doesn't offer a specific volume of data, but it charges 0.19 francs per MB, which is quite OK compared to the rest of the market. With Talk-Talk you would have to pay 9.5 francs for using 50 MB in a month (this is my monthly average if I don't use my phone as a modem), which is almost reasonable in my opinion.
Apparently Coop will appeal more to most people (it also has better tariffs for calls and messaging), but I mentioned both.
If you happen to know some other prepaid offer with an interesting data tariff please let me know.
I'd like to see Migros Mobile raising the bar. Their prepaid offer has better tariffs than Coop Mobile, but no data option at the moment...