Flash IP location
One of our reader, Daan, ported our services to an ActionScript 3.0 API to open it up for other Flash and Flex developers. Since we did not write the code, you can get more details (and probably support) here.
We have 2 servers. They are load balanced & highly available (ldirectord + heartbeat setup). Our goal is to have over 99.99% uptime.
We do not have a specific daily limit but queries that are at a rate faster than 2 per second will be put in "queue". If you stay below 2 queries/second everything will be normal. If you go over the limit, you will still get an answer for all queries but they will be slowed down to about 1 per second. Good programming practices such as not querying our API for all page views (you can store the data in a cookie or a database) will also help not reaching the limit.