Hockey Future has an interesting article up on who they rank as the best undrafted prospects in college hockey.  Now, I don't see a lot of East Coast hockey, but of the Western contingent there are two I wouldn't mind seeing the Blues sign:

Chay Genoway, D, 23
Senior, University of North Dakota

Genoway got his final year at North Dakota off to a terrific start, but it would all come to a halt on Nov. 13. when a hit by Aaron Marvin (CGY) forced Genoway out of the lineup indefinitely.

The Morden, MB native played in nine games to date and posted 10 points (four goals, six assists). All of his goals came on the power play.

Genoway is an offensive defenseman with great hands and on-ice presence. He is a fluid skater with good speed. He quarterbacks the power play with confidence and his puck skills are outstanding. What Genoway lacks in size (5’9/174), he more than makes up for in his leadership and work ethic. He is a tireless worker and leads by example. On a young Fighting Sioux team, Genoway has been invaluable in guiding North Dakota to another great season in the WCHA.

Genoway was off to arguably his best start of his collegiate career. An All-American West Second team selection last season, Genoway may have been on his way to another and All-American season were it not for his injury.

Genoway is one of those rare defensemen that is always a threat offensively.  The trouble is, of course, his lack of size.  The fear is he would continually get punished by bigger forwards, and durability would be an issue.  The fact he got beat up this season doesn't help his stock much.  Still, any powerplay could use his skills and hockey sense.  If nothing else, they would love him in Peoria.

Mike Testwuide, RW, 23
Senior, Colorado College

Testwuide (pronounced "testweed") may not rank among the top 50 scorers in the nation, but he’s gotten a ton of NHL interest and it’s not hard to see why.

The Vail, CO native currently ranks second on the Tigers in scoring with 30 points (20 goals, 10 assists) in 33 games thus far. His 20 goals also lead the team. Testwuide’s penchant for scoring at key times can be seen on his special teams play. Of his 20 goals, half have come on special teams – seven on the power play and three shorthanded. Testwuide has also posted a team-high five game-winning goals too. 

Testwuide is a power forward with size (6’3/220) who has excellent hands. He uses his size and strength well, especially in protecting and controlling the puck. He is very competitive and plays with a good deal of grittiness. Testwuide’s skating has steadily improved over the course of his collegiate career and that has gone a long way towards helping him become a dominant offensive force as well.

Testwuide is a legit NHL prospect in term of his size and hands.  I think he would have to show he is more of a two-way forward in the pro game, as I cannot imagine he would develop into a top flight pure scorer in the NHL.  But, seasons of 16-23 goals wouldn't be out of the question.

I would have to think a player like Genoway, who is more of a "take a flyer/depth guy" would make more sense for the Blues to actually sign than Testwuide, as the Blues have forwards already in the system they presumably feel could be as good (and better) than Testwuide.  Still, I think he'd be a plus for any organization.