rub elbows

Japan Times Online Oct.6の記事タイトルに出てきた下の慣用句と単語を覚えたい。
Technology, business rub elbows at STS confab
The annual Science and Technology in Society Forum, a three-day international gathering of scientists, engineers, university and government officials and corporate heads, kicked off Sunday with discussions on issues ranging from climate change to energy efficiency.
"rub elbows" は明らかに慣用句でしょう。辞書を見ます。
・Oxford English Dictionary: Associate or come into contact (with another person): he rubbed elbows with TV stars at the party
・McGraw-Hill Dictionary of American Idioms and Phrasal Verbs: rub elbows (with someone) and rub shoulders with someone: Fig. to associate with someone; to work closely with someone. (No physical contact is involved.) I don't care to rub elbows with someone who acts like that! I rub shoulders with John at work. We are good friends.
なるほど。そうであれば "confab" は "conference" と同じような意味のようですが確認します。
Verb: Engage in informal private conversation: Peter was confabbing with a curly-haired guy.
Noun: a) An informal private conversation or discussion: They wandered off to the woods for a private confab. b) A meeting or conference of members of a particular group: this year’s annual American Booksellers Association confab
"conference" より非公式と言うか、余り確固とした成果、目的を期待しない集まりのようですね。都会では毎日通勤電車内で "rub elbows or shoulders" が行われています。