Many people ask the following question about their baseball card collections, so I'm just going to post this question and the answer they received.

Is there a website that can track the real time value of a baseball
card collection?  I want to create a 'my portfolio' on a website which
will then let me organize my collection of baseball cards and give me
as close to realtime pricing/value on each card and the total
portfolio as possible.

Thanks for asking your question.  I have a basement full of baseball
cards so I'm interested in learning how much money I might be sitting
on :).

You asked us to find a site where you could track your baseball card
values in realtime similar to the stock market.  You want to be able
to put your cards in a portfolio for easy reference.

I believe I have found two sites that should fit the bill.  One is an
active online market, the other is from Beckett.

Beckett's site looks like it will work the best for you, although it
does come with a monthly charge.  It's hard to find the exact charge
on the site, but it looks like approximately 3-4 dollars a month.  To
get started, log into:

[ http://www.beckett.com/ ]

And head over to the 'my beckett' section.  Register a username and
password, and then proceed to the 'my collection' section.  It will
allow you to register 5,000 cards per collection (I believe you can
list multiple collections) and it will list pricing from the latest
Beckett price guide as the values change.

Thepit.com is the online, stock market-like marketplace with realtime
pricing based on the market's demand.  It is free of charge, although
there are fees for trading cards through the site.  You can find the
pit at:

[ http://www.thepit.com/ ]

The site says they're a subsidiary of Topps, but all brands of cards
are traded on the site.  It functions just like a stock market with
clever ticker symbol names for cards, and value determined in realtime
according to supply, demand, and the listed value price.

I logged into the site, registered my name, and found that the
'portfolio' section requires you to participate in the trading.  There
is, however, a 'watch' list that will allow you enter in as many cards
as you'd like with no obligation to trade.  You can follow their value
in real-time.

To find the watch list, click on the 'my account' button (after you
register, of course), then click 'watch list' to register your cards.
The pricing on the watch list will be updated in realtime when the
market is active.

I hope one of the two above sites will work for you!  I think the
Beckett site will have a more comprehensive database of card values
(they're the people who have been publishing values for years).  Best
of luck!  I'm about to register and spend a weekend tracking my card
values now :).