If you sometimes feel that using Twitter is like standing on a street corner with a megaphone trying to attract attention, you should try a Twitter chat.

These useful, often in-depth, conversations take place between users who tweet at a scheduled time with a common #hashtag – which allows tweets to be grouped together into a conversation view.

Most chats have a moderator to get things going with a few starter questions and keep the conversation flowing, and also to spread some cool vibes if the debate gets a little heated.

You can think of Twitter chats as something like a text-only conference, with the advantage that chats are available via Twitter’s search function or Tweet Chat even after the event has finished.

As well as possibly learning something new and making new contacts, taking part in a chat can help raise your profile among your followers and help you attract new ones.

Top 10 Social Media & PR Chats

As compiled and published by Simply Measured, here are the ten busiest chats ranked by number of tweets per chat session.

#blogchat (Sundays at 9pm ET)
Deals with both personal and business blogging and covers a range of themes including search engine optimization, WordPress and other blogging platforms as well as content writing. You’re quite likely to see a famous blogger join in from time to time.

#hcsm (Sundays at 9pm ET)
Discussing social media strategies for health care communication professionals.

#pinchat (Wednesdays at 9pm ET)
You guessed it, this chat is 100% Pinterest – interesting & novel pins and boards and how to market on the network.

#smmanners (Tuesdays at 10pm ET)
Aims to bring back “civility and charm to online communications”. Awh, bless. Doff your cap and enjoy such topics as the best way to ask for ReTweets and LinkedIn recommendations, as well as using social media to foster solid business relationships.

#brandchat (Wednesdays at 11am ET)
Brand chat has a different theme for each week’s chat. Subjects covered relate to both big and small business, personal brands and non-profits.

Both #mmchat (Mondays at 9pm ET) and #socialchat (Mondays at 9pm ET) are weekly question and answer sessions with special guests discussing social media.

#pr20chat (Tuesdays at 8pm ET)
PR folks discuss the changing nature of public relations.

On a similar note, there’s #journchat (Mondays at 8pm ET) which features conversations between PR people, bloggers and journalists.

One of the most popular chats for small businesses is #smbiz (Tuesdays at 8pm ET), a lively question and answer session between small business owners and experts.

There are hundreds, perhaps thousands, of active Twitter chats covering most subjects. A good place to find some of the most active chats is this public Google Docs list.

If you can’t find a chat related to your industry, why not start your own? If nothing else it’s a good excuse to contact and tweet with important people in your field.