A couple more suggestions. Most isp's offer x amount of webspace for the members. A lot of new folks dont realize this and you could ftp (or some are offering website upload now) your banner to your site. They allow much more bandwith usually then free sites.
Here are a couple other places that offer more bandwith and storage:
100mb hosting
600 mb bandwidth transfer
http://www.1weblord.com/http://www.freewebspace.com/Do a search on goggle for free webspace, and the amount of bandwith you would like as well. For instance: Free webspace, 100mb, 600mb bandwith.
Another thing is some of the sites if you email the webmaster will take your banner from you. I suggest you email the PO first. But a couple of the programs I am with just have me email the banner with my link to them.
I use both banners and ads to advertise I found that I get better results with ads but do get results with the banners. I also belong to a couple programs that have cash and points and points can be redeemed for ads. hillbilly hangout is great for this. Points ad up fast and you can advertise quite a bit banners or ads and still keep your cash. A few other sites do the same thing which I really love. I get ads and still can keep my cash.