Starbucks anyone?

Joking aside, co-writing is sometimes a difficult arrangement. Not from a location standpoint but from a responsibility standpoint. This came up in a previous thread recently:
Hey folks,
I live in Des Moines, and I really want to get involved with film but find it extremely hard to get started here in Iowa. What I was wondering, is there anyone on these boards who'd want to work together developing a script with me? Via email I guess. ...
Many of the people on this board are working on their own projects (writing, directing and/or producing). And while some take time to give feedback, taking on a new project is not at the top of the list. There are still those who may be willing but they need more information.
There are "writers for hire" all over the Internet. Writing is a time-intensive operation so one question is what is the reward? Few experienced screenwriters are idealists. Asking someone to co-write with you means laying out what you expect. Enticing a professional to work with you also means showing some knowledge of the industry. If necessary, educate yourself about screenwriting and film production (formatting, story telling, marketing, copyright, production, etc.)
An example of looking for a co-writer:
I have a wonderful story idea that I'm trying to develop and would like to engage an experienced screenwriter to help. I've developed some of the spec script but need some assistance with the action sequences of the storyline. This is a feature length script.
(This gives an idea of what you have already done and seeking. It also helps to know the length of the film {roughly: < 25 min. (short), 25-60 min. (episode), 60+ minutes (feature)} )
LOGLINE: Discovering a mysterious message, a young man rescues a princess with the help of a space pirate and wizard. Thrust into a galactic rebellion, can he use what he learned to destroy the evil overlord's death machine in time?
(You need to sell your story idea to prospective co-writers. In an actual logline you would make this MUCH BRIEFER. But for the purpose here, keep it tight and to two sentences.)
I cannot pay you but I am willing share credit and percentage of any profit realized. I am looking to produce and direct this myself. If interested, let's talk. If we feel positive about it, we can draft up an agreement of responsibilities.
This lets any screenwriter reading your post decide if it's an idea they are interested in developing. We each have our strengths (comedy, drama, horror, etc.). It states that this is a 'freebie' arrangement. Most produced screenwriters can't do freebies. They are often under a contract to a studio and so are even forbidden from reading outside scripts so the studios can't be sued. In some cases, you would need to formalize a contract with his/her agent. Still, many indie producers are writers and may be willing. There are also freelance screenwriters. So there are opportunities.
Let the reader know that you have already done some work and have some concept of screenwriting. Translating a story idea into a script is much more work (higher percentage). Simply editing a screenplay may be a smaller percentage. If both are marketing the script, that also is a responsibility.
There are different contracts out there for shared writing responsibilities. While I'm not suggesting you need a lawyer, I have seen co-writing 'agreements' go sour. One partner doesn't like the changes and suddenly after months of work, they go their own ways. It becomes a question of whose script is it now? Ideas cannot be copyrighted, only the written work. So it's best to agree up front about 'buy-out' rights. Just because you had the initial idea, once you bring in a co-writer, it becomes a shared idea and shared writing. There is nothing more frustrating in having a screenplay ready to go and now held up by legal issues of intellectual ownership. Production and marketing companies
loathe products where the rights are not straightforward; it can mean lawsuits and lost profit.
There are some outstanding collaborations too. Some writers have beautiful ideas but no concept of how to fit it into 120-150 pages. In many cases, the collaboration between the word-rich writer and the visual-rich screenwriter can work magic ("Screenplay by ... / Story by ... "). Many screenplays that are co-written are screenplays that have been optioned and/or purchased, then the producer/director/studio assigns new screenwriter(s) to assist or rewrite the screenplay to his/her needs.
The Internet opens up many avenues for finding creative screenwriters. Screenwriters tend to be a skiddish lot, not wanting to give away their "unique plot lines". If you are going to sell anything, you will need a logline. A good logline gives the gist in an interesting way without giving too much of the details. After you feel comfortable with a potential co-writer, honestly discuss a formal contract (a "pre-scriptual" if you will). This clears up responsibilities and ownership down the road. Then begins the fun of exchanging ideas and writing a screenplay.