Posting new content to your index page will pretty much do the same thing with Google.
Doing this on a regular bases will "teach" Google that you have new content and with a high enough PR (+PR3) Google will soon "learn" to visit your index page for that new content regularly.
With a PR4 site of mine, Google now visits the index page at least 2 times per hour and index's the new content right away, often mixed with existing content links.
This only works if you regularly have new content (ahh, and by new content I mean real content). However, this also works with currently indexed pages that have minor updates mixed in with new pages, again, as long as the content is real. The existing content will get a fresh looky-see from Google.
I hope this help.
Also, regarding the Yahoo! API, read this: "The Site Explorer APIs are limited to 5,000 queries per IP address per day and to noncommercial use."
Both wipe me out, so I am not reading any further. Be even if they did not, I really do not have the time to program for Yahoo! traffic, it is truly a waste of time: effort vs. benefit just do not match up with Yahoo!
[edited by: kamikaze_Optimizer at 9:12 am (utc) on Dec. 7, 2008]