Haloscan -- "With the daily signups numbering in the hundreds and the support requests that come with the new registrations, it would be tougher to implement the changes and additions we have planned without compromising the overall quality of service. Therefore, in the best interests of existing and future members, we have decided to close signups temporarily till we roll out the planned changes and additions." (Comments: So, why don't charge people for this service? Clearly there is an opportunity here.)