Thanks to a link at the National Archives of Hungary website to this free online European record portal, I have been reminded of a few good sources for Croatian and Hungarian genealogy and history that I had forgotten about - and I have found a few new ones.
Below are websites that I'll be visiting in the near future. Check the portal for your European country of choice from A to Z (well, Albania to Yugoslavia anyway).
Croatian Yellow Pages
Croatian White Pages
Adam Eterovich's Guide to Croatian Genealogy
Croatian National Library at Zagred in Croatian
Hungarian directory - Magyar Telekom
Web archive of Hungarian genealogy in English
Hungary.hu in English
National Széchenyi Library in English
And one more...
The European Library