Priceline has rolled out two new short-term features: A searchable display of winning bids for their Name Your Own Price hotel product, and an increased payout on its best-rate guarantee. Both are visible on the same page of their site, called the “Big Deal Guarantee.”

The display of winning bids is nice, but given that the BetterBidding or BiddingForTravel message boards exist to catalogue winning bids with greater precision, it’s not all that useful.

The best-rate-guarantee promotion — which expires March 31, 2010 — is potentially more interesting: Just like Priceline’s normal best-rate guarantee, the new offer only applies to their name-your-own-price product. But the terms and conditions of the deal are more generous.

While the normal best-rate guarantee was only valid for 24 hours after purchase, the new “big deal” guarantee is valid up until the day before check-in. That’s a much bigger window in which to find a better rate.

If you do find a lower publicly-available and -visible rate (i.e., no AAA or convention rates) for your hotel room on a website (it has to be via a website) and phone it in to Priceline, you’ll get a full refund, a $25 credit, and a $50 coupon for a Priceline vacation package.

But finding that better rate will be really tough. Priceline rates are deeply discounted because the name of the property isn’t revealed until you commit to purchase. But for a best-rate-guarantee, you’ll need to find a lower price for the specific hotel you won. And let’s be honest, it’s hard to beat a Priceline rate with a conventional publicly-visible rate. Priceline knows it’s not going to see many claims here, so this promotion is all bark, no bite.

On the other hand, they do introduce a portly new pimp character to be William Shatner’s sidekick in the ads. Tradeoffs.