A.C.
hi -
I agree with Sarah. Canada has actually banned baby walkers and the American Academy of Pediatrics has called for a ban on their use (http://www.healthychildren.org/English/safety-prevention/... ) and published a study about delays and baby walkers (http://aapgrandrounds.aappublications.org/cgi/content/ext...) .
Here are a list of possibilities
http://babyproducts.about.com/od/swingssaucersbouncers/tp...
http://www.consumersearch.com/baby-activity-centers
http://www.amazon.com/Baby-Einstein-Discover-Activity-Cen... (holds up to 30 pounds)
good luck!