Someone recently wrote me asking, where are the tools for sellers? She was frustrated after seeing a slew of new services for buyers. Obviously driving buyers to ecommerce sites is good for sellers, but I knew what she meant. There are lots of Web 2.0 innovations, but many are oriented toward helping buyers.

vFlyer is a new service for sellers that is certainly innovative. You can create one listing on vFlyer and have it appear across many online classifieds sites, and it has some nifty features as well (http://auctionbytes.com/cab/abn/y06/m10/i03/s03).

Vendors are not always in the best position to tell sellers exactly how best to use their service - sellers are amazingly innovative and think of how to use services on their own. eBay Motors is a perfect example. No one at eBay told sellers to start listing cars on the auction site, they just did. eBay capitalized on that demand, but they had not predicted it.

So while vFlyer currently seems particularly well suited to real-estate agents and car dealers, and while there are lots of possibilities for other vertical markets, I suspect sellers will come up with their own ways to exploit vFlyer to their advantage.

SingleFeed.com is set to launch on Monday and allows sellers to create one data-feed for submission to multiple comparison-shopping sites (http://www.singlefeed.com). Founder Brian Smith said merchants may be surprised that they can get as good results on shopping sites as they can on paid-search sites. Look for an announcement of this new service in this week's AuctionBytes Newsflash newsletter.

A Boston-area company is developing an online shopping tool that automatically sends consumers updates about products that interest them. Offertrax (http://www.offertrax.com) will allow visitors to receive RSS feeds from retailers with updates about products in which they are interested. The feeds can be delivered via the web or to mobile devices. While this is a shopping tool, it directly benefits online sellers by pushing their listings to shoppers who are interested in their types of items.

One service that I haven't written much about is Rapleaf, and I'm starting to think its time has come (http://www.rapleaf.com). When I first saw the Rapleaf portable reputation system, I was skeptical - the heart of a good feedback system is transaction-based ratings. But founder Auren Hoffman said that while it's unlikely Rapleaf could detect one instance of feedback fraud, it is very good at detecting what he calls ballot-stuffing. Rapleaf uses 110 fraud-detection heuristics, and Hoffman said the service is good at pattern matching.

I signed up (there's no charge) and you can see my Rapleaf rating on my blog (http://digbig.com/4neay). As more sellers make the leap to multi-channel selling, a portable feedback system is required.

Another "Web 2.0" service for sellers is Slide, founded by PayPal co-founder Max Levchin (http://www.auctionbytes.com/cab/abn/y06/m08/i08/s04). It provides a nice gallery feature for ecommerce listings that can also be ported to blog posts, websites, etc. FilmLoop also has an innovative photo slideshow service, including one geared specifically for eBay sellers (http://www.filmloop.com/create/ebaysellers).

But eBay sellers can feel smug that they've been using gallery tools long before Web 2.0. In fact, Jerry Lynch of AuctionHelper was way ahead of his time when he launched AuctionLynxx in 2002, and this year, he made it a stand-alone tool (http://www.auctionbytes.com/cab/abn/y06/m03/i07/s03).

eBay sellers have also tracked metrics like Average Selling Price and Sell-through Rates for a long time, and vendors have been introducing market-data and analytics tools in the last few years, such as Sellathon, HammerTap and Terapeak. Andale's new version of its market-data tool is far more sophisticated than the previous version, and Internet Business Skills launched Pyrolytics 2.0 recently (http://auctionbytes.com/cab/abn/y06/m09/i26/s04).

Imagine "mashing up" (excuse the Web 2.0 phrase!) an analytics tool with a gallery tool, so a shopper looking at an item in one listing can see a gallery of other items that they are most likely to be interested based on past shopping experiences? It would be like having artificial intelligence powering your gallery tool, driving consumers to buy more items from you.

If there's someone out there who has a Web 2.0 way of packing and shipping items that doesn't include enlisting the aid of children, pets or employees, let me know! Maybe I should give those Roomba people a call.