Let's pretend that you are a big sports fan and you want to get sports news about your favorite teams and players from a set of sources you find most reliable, and put those headlines on your website or your blog or your widget. Here's how, step-by-step.

DayPIs (version 4.4 and above) let you filter news from a specific set of sources by either using a source_filter_id or mentioning a list of source names in the API calls in the source_whitelist parameter.

Here is an example of what you can add to your API calls like topic_getRelatedStories or search_getRelatedArticles to get sports news from a list of sources (that I hand picked).

source_whitelist=ESPN&
source_whitelist=Sports%20Illustrated&
source_whitelist=BBC%20Sport&
source_whitelist=CBS%20Sportsline&
source_whitelist=Fox%20Sports&
source_whitelist=Sky%20Sports&
source_whitelist=Sporting%20News&
source_whitelist=Yahoo%21%20Eurosport&
source_whitelist=The%20Science%20of%20Sport&
source_whitelist=Cricinfo.com&
source_whitelist=Autosport

For e.g., here is a sample API call to get news about David Beckham -  http://freeapi.daylife.com/xmlrest/publicapi/4.4/topic_getRelatedStories...

To get related stories by topic, you need to either use a topic ID, or the canonnical name of the topic, which you'll see on www.daylife.com or in any DayPI call.

Below, some sample source filters for other categories.

BUSINESS:

source_whitelist=CNN%20Money&
source_whitelist=Forbes&
source_whitelist=Middle%20East%20North%20Africa%20Financial%20Network&
source_whitelist=Kiplinger%3A%20Money%20Monster%20Blog&
source_whitelist=Motley%20Fool&
source_whitelist=Business%202.0%20Blogs&
source_whitelist=Business%20Week&
source_whitelist=Fox%20News&
source_whitelist=BBC%20News&
source_whitelist=Guardian%20Unlimited&
source_whitelist=EUBusiness&
source_whitelist=The%20New%20York%20Times&
source_whitelist=Reuters  

CELEBRITY:

source_whitelist=TMZ&
source_whitelist=Perez%20Hilton&
source_whitelist=People&
source_whitelist=E%21%20Online&
source_whitelist=POP%20SUGAR&
source_whitelist=Hello%21&
source_whitelist=OK%21&
source_whitelist=Celebspin&
source_whitelist=Hollywood%20Reporter&
source_whitelist=MTV.com&
source_whitelist=VH1%20News

POLITICS:

source_whitelist=BBC%20News&
source_whitelist=CNN&
source_whitelist=The%20Washington%20Post&
source_whitelist=ABC%20News&
source_whitelist=FOX%20News&
source_whitelist=Guardian%20Unlimited&
source_whitelist=The%20New%20York%20Times&
source_whitelist=Reuters&
source_whitelist=Huffington%20Post&
source_whitelist=Reason&
source_whitelist=Time&
source_whitelist=ABC%20Online&
source_whitelist=Economist

SATIRE:

source_whitelist=The%20Onion&
source_whitelist=Humor%20Feed&
source_whitelist=CAP%20News&
source_whitelist=Smooth%20Operator&
source_whitelist=Weird%20News&
source_whitelist=Whitehouse.org&
source_whitelist=The%20Satirical%20Political%20Reporter&
source_whitelist=NewsBiscuit&
source_whitelist=News%20Groper&
source_whitelist=Weekly%20Dig