Yugoslavia...
 

I will be spending 10 days around Dubrovnik in June, with 3-4 days in neighboring Bosnia and Montenegro. Then, I'll spend two weeks in Slovenia in August, of which 3-4 days will be in Croatia. I am planning to buy one pre-paid SIM card in Croatia and one in Slovenia, but I was wondering whether there was any better option.

My needs: mostly incoming calls, with an occasional outgoing local call or SMS (in other words, the cheaper the better). A good data plan would be very nice to have, not much traffic needed (mostly GPS and some mail reading along the way). Micro-SIM needed (iPhone 4). And as said, I will start in June and will need it again in August. Any help is much appreciated.

Shuly

I would suggest a combo of two "international" sims.
For example PrePaidGSM: WorldSIM has incoming calls for free in 3 of your 4 countries.
and http://www.maxroam.com/Info/Rates.aspx?cur=EUR covers the other one.

You would receive calls for free.

Try to search here, you could find a nice combination. PrePaidGSM.net: International GSM Operators

And if you are talking little amounts of data in three different countries you might want abroadband (although that's technically postpaid).

Prepaid cards are cheap in all 4 countries, so you can get one in each country. Data is also rather cheap in Croatia while is terribly expensive in Slovenia, so forget about it and hope to find some free wifi. In Montenegro also data is not that cheap (5€ for 50MB).

International cards are usually more expensive to buy, but they could also be a good solution.

Thank you!
 

Thanks a lot for your replies, this is very useful.

Shuly

Slovenia
 

In Slovenia, you can buy a data-only sim card from Mobitel.si for 15 euro; this comes with 24 hours of unlimited data transfer. Then, you can top it up with increments of 5 euro (1 day), 10 euro (3 days) or 20 euro (10 days). See here:

Mobitel.si

They have both regular sim cards and micro-sim (for iPhone 4).

Shuly