I'm not sure about FishText but as I recall smsBug only takes about 100 bytes to send a SMS. If you only send a few per day it looks like 02 would never charge you for the data.

100 bytes? That's impossible. I doubt there's any compression algorythm that can shrink 160 bytes of text + overhead (e.g. recipient's number) to 100 bytes. Further you forget all the header information of the HTTP-request on TCP/IP-level. I fear you can't send any SMS over TCP/IP with less than 512 bytes.

Take this example: the request has 50 bytes, the response 286 bytes and that's without those 160 bytes, which need to be transferred and without the at-least 12-digit number of the recipient. Furhter the request should contain some authentification information. So no way to stay below 512 bytes!

I'm assuming this is O2 UK. For everyone's reference, they charge £3/Megabyte within the EU and £6/MB worldwide (O2 roaming page here). This translates to just under £.003 per KB within the EU and £.006 per KB elsewhere. The latter is just over Virgin UK's £.005/KB, though that extra £.001 may be worth it for those wanting greater international coverage. Either way, it sounds like this is the cheapest option for low usage data roaming in Europe.

I do think they should specify that their billing is per KB. My first look at that pricing implies that you get charged in 1MB chunks.

Using O2's international coverage check, it gave this info under the network specific information for Panama:

"You can use GPRS data services and media messaging on this network.

O2 customers roaming on this network will not be able to use 3G services."

Nepal and Peru also say you will not be able to use 3G services but with no mention of GPRS at all. These countries may simply not have HSDPA or UMTS, but still have GPRS or EDGE, which is all you need for sending SMS as mentioned in this thread. I would guess that's the case but it would be worth inquiring if you're headed to one of the above mentioned countries - except Myanmar, which only seems to have one network at this point and no realistic options for phone service as a foreigner.

Nepal and Peru in fact don't have 3G-networks, as you can see at the GSM.

OK. I was wrong. Here is the info from the smsBug FAQ:

Q: So how much GPRS traffic does smsBug typically use?
A: Below is a table of typical smsBug transactions and the traffic generated by them.

Registering (Part I) | 422 bytes in | 240 bytes out
Verifying password (Part II) | 420 bytes in | 188 bytes out
Sending a 160 character SMS | 422 bytes in | 500 bytes out
Synchronizing 5 Contacts | 709 bytes in | 194 bytes out
Requesting remaining credits | 422 bytes in | 155 bytes out
Setting Delivery Report status | 421 bytes in | 188 bytes iut
Purchasing credits | 422 bytes in | 260 bytes out

This afternoon I send an sms with Fishtext and according to my Nokia around 700 bytes where send (sum of up- and download).

3 UK is also £3/MB in Europe and several other countries including USA

but T-mobile UK cut its rates a couple of months ago to £1.50/MB

and I think someone on here has recently mentioned similar rates with other networks (T-mobile Germany?)

Well I know that it's interesting enough to buy a 02 uk card and have some credit from fishtext, there are enough countries where it works. Maybe it works for some of the countries as well where it's said there is no 3G but where nothing is written about gprs, when not I can always buy a local prepaid or use one of my international cards. The countries where it where it works according to the site of 02 already saves me enough. :)