Unclear Concerning Delegation for IN-ADDR.ARPA

[Bill Polhemus]

I'm not real clear on this.

If I have a set of IPs from my ISP (in this case an "itty-bitty" network, CIDR /29), can I get "delegation authority" myself?

IOW, what if I DO want to set up DNS here on my network, can I do the "reverse mapping" myself, or does someone else have to do it
for me?

I have tried using granitecanyon.com, but I haven't had much luck with them on one of my domain names. The first one I set up did
fine, but the second...no go.

I guess I had my ISP delegate to granitecanyon.com, but if I decide to go my own way, to whom must I go for the "redelegation"?