It sounds as though you are accessing 802.11g networks and your network card isn’t taking full advantage of the network speed available. Even though you have an integrated wireless card in your laptop you can purchase a wireless G network card. This will allow you to connect to faster 802.11g standards when that network is available.
If you know that you will be traveling to locations where 802.11g is available and you only have an 802.11a or b card in your laptop purchasing the second network card is a cheaper alternative to buying a new notebook just for the wireless connection speeds.
Set up shouldn’t be difficult; you just designate the 802.11g network card as the choice for connecting to the 802.11g network you will be using. When you don’t need the wireless G option, you can remove the card and store it in your laptop case.