Is there anyway to improve my upload speed of my broadband connection or is it limited by my ISP? I`m getting a average of around 250 kbps which seems very slow. Maybe this is a normal upload speed?
256Kbps is fairly typical.
Before my ISP switched me to 3Mbit download, 384 Kbit upload, I had 1.5Mbit download 256 Upload.
Upload speeds tend to be much lower than download speeds for 'normal' residential DSL, cable or wireless broadband connections. The 'A' in ADSL stands for 'a-symetric'. The idea behind it being that the vast majority of home users don't need more than that anyway, plus higher speeds can be sold for a huge premiuim to business users that *do* need the speed and can afford to pay for it.
If you need high upload speeds then you either have SDSL (symetric, where upload and download speeds are the same) or dedicated circuits like T1's and the like... but expect to pay 10+ times as much for that tier of connection as you do for 'normal' ADSL/cable.