yum yum yum yum yum

Having problem using yum with proxy?
Add proxy and timeout in /etc/yum.config:
proxy=http://172.10.20.30:4000
timeout=180

Hate download of updates/primary_db and all that automatic refresh?
yum --disableplugin=refresh-packagekit list  

Download only, don't install:
yum --downloadonly install PACKAGE

Try following commands:
yum list | more 
yum list installed
yum info curl
yum deplist curl
yum repolist