When ppl talk about tagging in Social BM sites - do they mean putting the keywords in the field marked "tags"?

Tagging is the process by which many users add metadata in the form of keywords to shared content.

Yes, of course. Tagging in social bookmarking sites, or article submission as well as directory submission sites is essentially putting in relevant keywords in the Tags field. This will make the content more easily searchable through search engines.

Yes tagging and title is most important part of Socialbookmarking...

Originally Posted by HussainGardezi

Yes tagging and title is most important part of Socialbookmarking...

I Agree..

The use of meta tags in web pages are often required by search engines as a source of information to help them to decide how to list and rank your website. Meta Tags are not always required, but as a rule of thumb, it makes more sense to take advantage of them than to leave them out.
It is a simple process to add Meta Tags to web pages. We have created this free Meta Tag generator, to help you make the most of your submissions.

Tagging is useful for searching the topic that visitor want to know

Yes, tagging is indeed useful and a must in my opinion if you want to maximize your sites exposure since it raises the possibility of being found.