If you're just trying to set up when to do raids and would be consistent with it thereafter, you can have everyone put events on a shared Google Calendar and look for gaps (or overlaps, depending if you use events to indicate free time or unavailable time).
I'm currently programming Warmath, which is in closed beta (you can request access for your guild by PMing me on
http://forums.subcreation.net/), which includes raid signups, though it is part of the greater DKP system.
If folks have suggestions as to what they'd like to see in raid sign ups, I'd love to read them, as I'm planning to improve Warmath's sign up system. Specifically, here's what's currently there:
- Admins can schedule a raid, indicate what times it starts and what bosses
- People can sign up
- They're listed by satout dkp (a concept Warmath uses to keep track of who's sitting out, so we can rotate people in and out, given class balance)
- Each boss marked is also listed, with people sorted into Tank/Heal/DPS along with the loot people want (Warmath uses wishlists to have people mark what loot they want)
Features I'm planning to add:
- Letting people set whether they're Tank/Heal/DPS (e.g. feral druid would be only Tank, Shadow Priest only DPS, MS/Flurry warrior could be Tank/DPS) [not sure if I want a 'main tank' field, since there's generally only 1 such person within a raid and he or she is known]
- Condensing sign ups to one sign up per instance, per week -- we currently do Karazhan over 2 or 3 days and folks don't like to sign up 3 times and would rather just sign up once and indicate what days they can or can't make.
- Indicating what times people sign on and need to sign off, so as to provided an "estimated feasible starting time" and "likely end time" as judged by parameters that can be set (e.g. need X tank, Y Heal and Z dps)
- Changing it from the sign up/not signed up dichotomy to a sign up/unknown/can't make it tuple.
Thoughts on other stuff you'd like to see?