This is a list of SIOC-enabled sites. This list is also available in RDF here and mentions SIOC data URL.
aetherworld.org - Alexander Graf's blog
AI3:::Adaptive Information - Mike Bergman's blog
Alexandre Passant - Personal weblog using Dotclear exporter
Augmented Cognition Blog - AugCog from a garage perspective
B:\datenbrei - Wordpress2.0, mixed language content
#B7erge - Wordpress1.5, all german content
Bamblog - by Jan Schmidt, in german
The Blog of Athos - by Juan Miguel Gomez
Casual.info.in.a.bottle - Personal blog in italian and english about Web and Semantic Web
La Comunidad de AsturLiNUX - AsturLiNUX blog community
contentfree.de - Rolf Strathewerd's blog, german content
Dobrometr (RU) - similar GetThingsDone service
Future Trends - a ThirdForce R&D blog
The Hundredth Monkey Phenomenon - by Rob Gonzalez
hyperdata.org/blog DannyAyers 's WP install
identi.ca and other laconi.ca-powered sites.
Infopirat - Drupal based news and blog site, SIOC enabled
Innovative SEO Tools - RELAX SEO Services - Innovative Tools and Training
journals.ie - A Wordpress Multiuser site, all the blogs are SIOC enabled
Needle Blog - A WordPress site for sharing news from the Needle (semantic digital libraries) community
NoticIEEEro - A WordPress site sharing articles and announcements about IEEE Region 9, Latin America and the Caribbean, mainly in Spanish. The blog is SIOC enabled.
Operation:Teleport - did you ever want to be someone else?
OpenLink Virtuoso Tutorials Data Space - collection of Virtuoso tutorials covering SQL, XML, RDF, and Web Services
randgaenge.net - a blog on Social Software
semwebdev Keith Alexander's blog.
Take a look around the world - Sergey Lukichev's travel blog
Weblog Data Space - Kingsley Idehen's Blog
Creative Commons Car Pictures -- Photograph Collection tagged w/ semantic topics that outputs SIOC
Firefox users can use a few extensions to detect and reveal SIOC and other RDF data on web pages
OpenLink Data Explorer (ODE) reveals SIOC, FOAF, and other RDF data found, extracted, and/or generated via RDFa, GRDDL, and other means, and displays a status bar icon. Clicking the icon, or using the "View Page Description" or "View Linked Data Sources" contextual or main menu options will allow you to browse through the corresponding RDF data. Install the ODE Extension.
Semantic Radar detects links to SIOC, FOAF, and generic RDF and RDFa data (via auto-discovery information) and displays status bar icons. Clicking on an icon will allow you to browse the corresponding RDF data. Install Semantic Radar
If you are not using Firefox, you can use these server-hosted tools through other Web browsers --