I like that Google has local adwords searching within my city limits, but I can't figure out if Yahoo's Local search is comparable.

Anyone know how they are similar/different?

They both have similar pay-per-click ad programs. Basically though, Yahoo markets itself not as a search engine, but as an Internet directory. Where as Google is a search engine. Some differences I found when advertising with both of them at the same time.
..  1) Yahoo requires you to put money into your account with them and maintain a balance. Say for instance, your spending about $10/day on advertising clicks. They want (I believe) 3 days worth of funds always in your account ( i.e. $30).

Every time your account goes under that amount, it will automatically debit the credit card you have on file with them to place more funds into the account.
 Google allows you to carry a negative balance (like a running tab) with them until your scheduled time of the month to pay your bill.
 Then they debt your credit card account. If it looks like your running an extra large tab (mine was every time my bill got over $500), they will go ahead and debt your card to make sure you don’t leave them with the bill.  2) Yahoo gets less traffic then Google. But it isn’t necessarily a problem since you will need to set a maximum daily budget with either of them and you will most likely always reach that amount with either company.

 3) You have to wait for administrative approval of all of your ads with Yahoo, which can sometimes take a few days. With Google, your ads go up right as you submit them and are up in seconds.
Google’s administrators will pull the ads down later if they deem them unappropriated.
This means no waiting for someone to review your work before it’s up and running.  4) One last thing. You may have hard time getting any remaining balance you have in your Yahoo Ad account back after you are done advertising and close the account.

I have been trying for years to call, write, everything to get the $89 that’s still sitting in my closed account sent back to me.
Every time I contact them they say "OK it will be sent to you within 2 weeks" and every time it never does.
This is not a problem with Google as you run a tab with them and they bill you for only what clicks you’ve received.    Hope that info was of some help lol!