Meitar

My Two Cents integrates your WordPress-powered site or blog’s commenting features with BitCoin.
My Two Cents is extremely lightweight, completely automated, and extremely unobtrusive. Simply provide your BitCoin address(es) and the plugin takes care of the rest. For best anti-spam results, I recommend enabling WordPress’s built-in “Comment must be manually approved” option in its <a href="https://codex.wordpress.org/Settings_Discussion_Screen" rel="nofollow ugc">Discussion Settings</a>.
By default, My Two Cents automatically generates a unique BitCoin address for each comment. This feature relies on the “low-trust” <a href="https://blockchain.info/api/api_receive" rel="nofollow ugc">BlockChain.info Receive Payments API</a>. Your commenters send BTC to the automatically generated addresses, and BlockChain.info forwards the amount to the address that you choose.
Optionally, you can also use the simpler “transaction polling” method. This will add a field to your comment form asking for the commenter’s BitCoin address. Once each hour, My Two Cents queries the BitCoin blockchain (the public accounting ledger of transactions) and searches for funds transfers to your address from the commenter’s address.
When a valid transaction is detected, My Two Cents acts on the associated comment(s). 
Maintaining this plugin is a labor of love. However, if you like it, please consider <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=meitarm%40gmail%2ecom&lc=US&item_name=BitCoin%20Comments%20WordPress%20Plugin&item_number=bitcoin%2dcomments&currency_code=USD&bn=PP%2dDonationsBF%3abtn_donateCC_LG%2egif%3aNonHosted" rel="nofollow ugc">making a donation</a> for your use of the plugin, <a href="http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2Fs%3Fie%3DUTF8%26redirect%3Dtrue%26sort%3Drelevancerank%26search-type%3Dss%26index%3Dbooks%26ref%3Dntt%255Fathr%255Fdp%255Fsr%255F2%26field-author%3DMeitar%2520Moscovitz&tag=maymaydotnet-20&linkCode=ur2&camp=1789&creative=390957" rel="nofollow ugc">purchasing one of Meitar’s web development books</a> or, better yet, contributing directly to <a href="http://Cyberbusking.org/" rel="nofollow ugc">Meitar’s Cyberbusking fund</a>. (Publishing royalties ain’t exactly the lucrative income it used to be, y’know?) Your support is appreciated!

My Two Cents

Get BitCoin from commenters. Auto-approve comments that include a BitCoin donation. Fight spam with BitCoin microtransactions.

Luiji

This widget provides a nice, optionally thumbnailed list of Zazzle products 
based on query parameters you configure it with, including the store, search 
terms and sorting mechanism. Unlike other Zazzle widgets, this one only uses 
the referral identifier that you give it, or none at all if you do not 
specify one (you know who you are — wink).
Additionally, this widget can be embedded into your posts and pages with a 
shortcode. These shortcodes look something like <code>[pizazz query=asparagus rows=8 
columns=3]</code>.
I use PCRE to parse the RSS feeds. If Pizazz does not work, make sure that PCRE 
is available in your PHP installation. It is available on most PHP servers.
Pizazz is multisite-compatible!
NOTICE: I don’t have a testing staff, and my ability to think of every 
potential problem is limited. If you have problems make sure to report them 
to me or I won’t know they exist for a long time!

Pizazz

A widget that pulls a Zazzle feed and displays products based on a query

My Two Cents vs Pizazz