The only problem is I don`t know how to temporarily log onto a foreign service provider to get you onto the net. When in the Middle East last month I used an internet cafe to manage my e-mails.
If you just want to be able to collect and send your e-mail why not try click here. Go to advanced log in and enter your mail server details. (you can find that information from outlook TOOLS >ACCOUNTS>PROPERTIES) then enter your username and password. From there you can do almost everything.
You could try the ipass system. Costs £5 per month above the standard ISP account charge (£10pm with Mistral), and 20p per minute while online. See click here - incidentally, I rate Mistral very highly as an ISP.
Not cheap, but the coverage is superb.
Or investigate AOL - they certainly used to have a comprehensive global POP network.
If you know you will be able to access the Web via someone else's account (they will obviously have to share their username, password and dialup number) it would be easier to just use their PC and access your mail via an ISP's Web-based mail portal (as Mistral and many others do), or use the mail2web service.
I signed up for everyday.com in (I think France) and then played around with the registration to find the local dial-up numbers for belgium and switzerland (for when I'm travelling). Half the time this works fine, the other half I never seem to get connected and I have no idea why. also my btopenworld number doesn't seem to work everywhere in the UK any ideas why?