Need help regarding 2 dsl connection

plz i need help is there any device that can connect two ptcl dsl connection and combine both speed or any two different isp's dsl into one connection ?

i search a lot of forums and sites and found this thing

d-link DI-LB604

yes it called Dual Wan Router :)

search Internet you will find one :)

search for load balancer..

what is load balancer????? write details.