What incentive is there for someone to run their own Ripple client/server in order to make it an actual decentralized system? With Bitcoin, you can mine to generate new bitcoins and collect transaction fees. Is there a Ripple equivalent?
There is no mining in Ripple. The incentive to run a client is to use the Ripple network. There are several incentives to running a server. The main one, as Lohoris suggested, is to support the network. This is the same reason Bitcoin nodes relay transactions.
From the wiki:
Anyone whose business relies on the network: Gateways Merchants Arbitragers Day traders Anyone who wants to support currency choice: Digital rights groups Libertarian groups Individuals Anyone who wants to support the underbanked: Organizations Individuals Anyone who wants to provide a public service: Universities Anyone who provides hosting services for open source projects
As a high-volume merchant or arbitrager, running a node is the most efficient and reliable way to participate in the network. If nodes feel you aren't pulling your weight, they can either disconnect you or impose a proof of work requirement on you to remain connected to them. This is because legitimate high-volume queries are indistinguishable from abuse. As a fully-participating node, you can see transactions before they're voted into consensus sets.
I looked at the bitcoin gateway sample code on github, and its README said that to use it I need to set my ripple account up to forward what seem to amount to customer or routing numbers, basically so the app can match up incoming ripples or bitcoins with each other.
Its instructions how to do that were to send a command to a ripple server;
Here is the clincher, the reason I would want to fire up a ripple server of my own:
THE COMMAND SHOWN INCLUDES SECRET KEY.
In other words, in order to set my ripple acccount up to be able to have a web app convert between bitcoins and ripples, sending out bitcoins from my bitcoind on receipt of payments on the ripple network or sending out payments on the ripple network on receipt of bitcoins by my bitcoind, I AM SUPPOSED TO PASS MY SECRET TO A SERVER.
If I do not run that server myself, my so called secret would no longer be secret...