If you aren't concerned with recording...TrendNet's IPViewPro v4 works well inside AND OUTSIDE of your home network. You just need to have to config files for inside and outside (the the outside one will be your ISP IP address with the proper port for each camera)
The recording is .avi and limits each file size to 50MB which works out to about 7-10 min. So you'll end up with hundreds of files if you want 24/7.