Network Load Ballencing question?

[Vectorman]

+-----+ CABLE 192.168.1.XX +------------------+
| |------------------->| LINUXWORKSTATION |
| 8 | +------------------+
| |
DSL +-------+ STATIC XXX.XX,XXX.XXX-XXX | P | CABLE 192.168.1.XX +------------------+
----->| MODEM |---------------------------->| O |------------------->| DVDBURNER |
+-------+ | R | +------------------+
| T |
| | DSL XX.XXX.XXX.XX +------------------+
Cable +-------+ +------+<-DHCP/192.168.1.X->| S |------------------->| LINUXSERVER 1 |
----->| MODEM |-|W/LRTR|------------------->| W | CABLE 192.168.1.X +------------------+
+-------+ +------+ | I |
| T | CABLE +------------------+
| C |------------------->| LAPTOP |
| H | +------------------+
| |
+-----+

Above is a graphic representation of my Home Network.

My Question is:
Is there a way to Load ballence the two Internet Connections, In effect Doubling my Internet Speed?

If so, Do I have to purchase a Network Load Ballencer or can I do it with the Linux Software that I have.

Thank you
Joel