If I have two Internet connections is it possible to combine their speeds using load balancing or some other method?
For example if I have two Internet connections of 500 meg a piece is it possible to combine them to get 1 gig, or or something in between?
If you want the combined speed to be available to one device - short answer, no.
Long answer involves applying for an AS, configuring eBGP with your providers and a whole load of enterprise stuff.
You can route traffic to and from high volume traffic devices through a different connection from interactive use, e.g. do your backups, synchronisation, updates, etc. through a bulk link.
Bart...