Getting together sound quite easy but it will require some expenses, and there will be nothing rewarding for anyone to just host bitcoin conference in their area. We are only having fewer conference by some big bitcoin related media outlets which are trying to gain some popularity among investors so they can get advertisers for their outlets.
Bitcoin will go to mainstream without any advertising, many people soon gonna realize the potentiality of bitcoin transactions and demonetization along with infinite inflation of cash will force many investors towards bitcoin.
it doesnt need to be expensive to 'get together' start local as a 'meetup'.
arrange to all meet at a cafe/bar a certain day/time each week or month.
usually you may only see 5-15 turn up. so no costs. its just a few guys siting in a cafe/bar drinking their own drinks
learn what local skills locals interested in bitcoin have. start discussing what local shops the majority all use, to se the most popular choices you all would want to see accept bitcoin and plan on what to do to help get local stores to accept bitcoin.
this may as simple as where a bitcoin buyer sets up a fiat bartab with the store. and then gives the store a QR code.. then any customer asking to pay with bitcoins can be shown the qr code. the shop worker just checks a phone browsers bookmarked link of a blockexplorer to see if funds arrive.. and then the store manager takes the cash amount out of the bartab.
(that has been found to be the easiest intro to offer to a business to try out bitcoin acceptance risk free)
usually good practice to ask the cafe/bar you intend to use regularly for meetups to try out showing qr code and checking blockexplorer when their customers ask to pay with bitcoin. it hones your confidence and experience of asking a business to accept bitcoin. while helping the bitcoin buyer have a regular bitcoin income. and getting your first local merchant to accept bitcoin.. (then let it grow from there)
as things grow and more turn up. say 15-50 find another venue that can cater to the amount if the cafe/bar cant cope. some have found they simply ask the bar what day is their slowest/lowest occupancy, meaning more room for bitcoiners if there are less random people there. and arrange the meetups for that day. thus not putting a strain on the bar.
if 50-100 want to turn up then set up an attendance fee of say 100th of the room hire
usually you can hire a room with capacity for 100 for under $100 for a couple hours($1 per attendee) and less for the rom hire/attendees ticket in developing countries. in short split the cost
once things start getting bigger and you want to invite international spokes people to attend. then make the attendance fee (ticket price) equate the cost of hiring the even larger venue for the day.