Magento

How hard would it be to use the USPS API (or UPS, FedEx, etc.) to calculate approximate shipping times for packages based on the same info we use to calculate the approximate shipping costs (weight, orgin Zip, destination Zip, etc.)?  I know, for some of my customers, the cost is secondary to the delivery time.  I’ve seen people pay more for shipping than the product just to make sure it gets there when they need it.  So would this be tough to do?  Would it be best to modify the existing shipping modules or would it be better to rewrite a “new” and “improved” shipping module for each of these?

MunchyMonster

Maybe this can help:
http://www.ups.com/content/us/en/bussol/offering/technology/automated_shipping/online_tools.html

http://www.magentocommerce.com/group/blog/action/viewpost/370/group/222/