A web service that would help so many web developers

Yesterday, someone wrote an Japanese email to our church using the form on the church homepage. But, we couldn't read anything, because of encoding problems – all characters were like complex traditional chinese kanji you would only use in names.

I was surprised with this, as I had tested the system in various browsers on my mac with no problems at all. (Yes I should have tested it on Windows, but you know…) I even have IEv6 running on Wine - the problem is, it doesn't have support for Japanese characters (or maybe it just needs a Japanese font). Therefore I didn't test it with that.
The person who wrote the email, was apparently using IE 6 on Windows – I already told you the result.

Wouldn't it be nice, if there was a web service or a browser that would show your web page rendered in all major browsers and you could test the functionality in all browsers? I haven't found such service yet. It would save so much work.

Please someone, make this for all web developers including me.