Join Gixen today!
I have been using Gixen myself for trying to bid on items on Ebay. This link which I distrubute allows access to a reference so you can sign up to Gixen. I highly recommend it!
Gixen is 99+% reliable and is very secure. No download required and yet Gixen automatically places your bids on eBay at the last moment while being automatic; which allows for you to be off your computer. The free service allows for unlimited snipes and also you can buy a mirroring service which will allow for another server for backups in case of emergencies. Again, I highly suggest it!
