I assume people are playing guitar with the intent of eventually getting together with other musicians. Post your classified for your ideal band which you would post on craigslist, etc. If you already have a band, post an ad for a band which would be even more ideal. Type of music. Influences. Age limits. Type of venues, etc.

Here's mine:

Guitarist looking to start intermediate level straight ahead jazz band, meaning playing standards straight from the Real Book(s). Must be able to read and/or know a fair amount of songs. Repertoire would mix Latin, Swing, Ballads, and modal. Ideal instrumentation would be a quartet: with saxaphone, bass and drums. Looking to gig eventually, but gigs not main motivation. Preferably mid 20s and up for maturity and social purposes but all ages welcome.