Hi dg7feq,
do you know of other services like DialNow? I will try to check out this service, but if it's barred like you said it might be - which other one would you recommend?
Your response is greatly appreciated, by the way!

Cheers,
Pawel

there are many more betamax clones that might use different access numbers.

In case that these accessnumbers are put on a list by o2 the only solution would be to setup your own callthru system.

You register a local german number for free at www.sipgate.de
Take your dialnow account.

Open an account at pbxes.com and register the sipgate number as trunk and dialnow account as trunk.

In incoming routing you can choose callthru pin to activate your callthru. (don't know if it works on the free accounts, otherwise a soho account is available at 2,95 a month)

Call your own sip number, enter the pin, and you get a dialtone of the pbx and dial the number you want.

Justvoip.com will work on a sip device, there website only mentions that you can use a softphone/p.c

SIP port : 5060
Registrar : sip.voipbuster.com / sip.justvoip.com / sip.voipcheap.com
Proxy server : sip.voipbuster.com / sip.justvoip.com / sip.voipcheap.com
Outbound proxy server : leave empty
Account name : your VoipBuster / justvoip ect, ect, username
Password : your password
Display name/number : your VoipBuster username or voipnumber
Stunserver (option) : stun.voipbuster.com

You can use sip.voipbuster.com/sip.voipcheap, ect on any of betamax acounts.
All these sip.names go back to the same server!