Many venues (for geek events and for anything else) have gendered restrooms, divided into men's and women's. There may also be wheelchair accessible restrooms, usually private and not gender-specific.
Gender imbalance and restroom assignment
Since many geek events have a strong gender imbalance (90% male is common), and are held in public spaces which commonly serve more gender-balanced crowds, there are typically more women's restrooms available than are required by the number of female attendees.
In some cases, events have attempted to redress this imbalance by reassigning women's restrooms for use by men. In one notable case (OSCON sometime around 2007?) this resulted in all bathrooms in the main conference area being assigned as men's bathrooms, so that there were no women's bathrooms available in the area at all. Conversely, some majority-women geek events such as BlogHer have assigned men's bathrooms for women's use, resulting in men having to walk some distance to find a restroom.
Problems with binary arrangements
- Trans and genderqueer people (particularly trans women) often are unsafe in both restrooms, as they may be harassed or attacked for their gender non-conformity in either restroom, or have management or police object to their choice.
- In addition to being unsafe for anyone who cannot or does not conform, the arrangement enforces the Gender binary in a highly visible way, forcing everyone to announce an affiliation multiple times a day, and thus is problematic for anyone whose identity is non-binary.
- Carers of children who are not of the same gender often have considerable difficulty deciding which room to use when their child is not old enough to go alone, especially once the child is old enough to have an opinion themselves.
- Facilities for changing babies' diapers are sometimes associated with the women's facilities, which means that caretakers who wouldn't usually use, or be welcome in, the women's restrooms may either have to enter them, or not be able to use the facilities.
- Brenda Wallace found that her male partner had a great deal of difficulty accessing baby change facilities in New Zealand 
Problems with accessible arrangements
Carers for children sometimes prefer to use the wheelchair accessible restroom where they can be alone with their child. Sometimes the change tables are set up in these restrooms. This can deny access to the rooms for the disabled users they are designed for, especially if the venue hasn't allowed for the demand from both carers and disabled users.
If the able-bodied restrooms are oversubscribed, some able-bodied attendees will use the accessible restroom, denying access to disabled people. This may also start disability policing (criticism of anyone seen entering the accessible restroom who isn't judged to be disabled), which will affect invisibly disabled people.
In this case, shared restrooms with stalls are available but are not assigned to a particular gender.
These arrangements do not solve accessibility for wheelchair users or the requirement for children and carers to have larger stalls or small rooms and baby change tables, and these still need to be provided separately. Some cis women say they don't feel safe from assault when not segregated from men in restrooms, but respecting this with separate restrooms can be sub-optimal for trans and non-binary people, as trans women are often unsafe from assault in segregated ones.
Private gender neutral restrooms
In this case, entire private lockable restrooms are available for everyone. These solve many of the problems with shared restrooms in general, but is expensive to build and hard to obtain if hiring existing larger venues as many geek events do.
These are private lockable restrooms designed for carers with small children. They will have change tables and might have smaller, lower toilets for small children and adult sized toilets as well. These have similar problems to private restrooms in general: they need to be provided by the venue at considerable cost. They may not be accessible, which means that disabled children or disabled carers of children may still not be able to use them.
Inclusive signs and labels that are prominently posted can discourage discrimination and allow people to make restroom decisions that make sense for them.
California rest stops have signs that announce that carers of another gender are allowed to accompany a person with disabilities into the restroom.
The Eliot Center in Portland (host to Open Source Bridge in 2014 and 2015) has "Or those who identify" signs below each binary gendered restroom sign. Open Source Bridge 2015 attendees modified those signs to be more inclusive
- Blue-taped over the "Or", rendering the signs "Women: Those who identify" and "Men: Those who identify"
- Wrote "Are" on the blue tape, rendering the signs "Women Are those who identify" and "Men Are those who identify"
- Added descriptions of the contents, such as "mini trash in stall" "changing table" "individual cubicles" and "urinals", to each restroom. Happily, the restrooms designated for men have changing tables.