I finished writing a (VERY) simple website over the weekend to send out email alerts when a specific bitcoin data source goes above or below a threshold. by data source i mean one of (high low avg vol last buy sell). Currently, i am only tracking mtgox, but i will probably add more data sources in the future. The site is live but in beta mode, so it should be reasonable to expect that any data you add to the site might be deleted or anything like that (i would at least send out an email before this happens anyways). I designed the site to be compatible with very simple automation, so you could easily automate this in a perl script or whatever. the password is really just to prevent people from setting alerts on someone else's email, not really meant for security (since the only piece of private info is the email anyways). passwords are salted and sha2 hashed, so they are secure themselves, but please don't use any passwords from important accounts. I will probably convert the form to a POST form in the near future, but for now it is just a GET form.
To use the site, register an email address (with password), then add any number of alerts you want. Be warned that data is refreshed every minute and that your alert will send every minute that the condition is true. so be careful when setting your high and low, otherwise you could expect a lot of emails.
The website is http://btcalerts.errorok.com/
As i stated earlier, i just wrote this website this weekend, so it is very fresh. I welcome suggestions for improvements. Let me know what you think.
Oh, and mods, i would eventually like to post this in the main sections (not yet, but once i clean things up and make some improvements). Thanks.