Can we know anything about Jesus' appearance from the Bible? We know something about Jesus' clothes, that He wore sandals and that He wore a seamless undergarment.

Are there any other clues in the Bible as to His physical appearance?
There isn't much, and that itself is telling.  Isaiah mentions a couple of things prophetically--first, that His appearance was not going to be particularly special:


  For he grew up before him like a young plant, and like a root out
  of dry ground;  he had no form or majesty that we should look at him, 
  and no beauty that we should desire him.  3 He was despised and
  rejected by men; a man of sorrows, and acquainted with
  grief; and as one from whom men hide their faces he was
  despised, and we esteemed him not.  Isaiah 53:2-3 ESV


and secondly, that He would become pretty marred, which is understood to have occurred at His scourging prior to the crucifixion:


  As many were astonished at you—his appearance was so marred, beyond
  human semblance, and his form beyond that of the children of mankind 
  Isaiah 52:14 ESV


Aside from these prophecies, there is nothing that really indicates what He looked like.  We do know that children wanted to come to Him, so He likely looked normal enough.  The fact that there isn't anything mentioned about His appearance is an indication that there probably wasn't anything out of the ordinary.  

King Saul was head and shoulders above everyone else, and that was notable.  Nothing like this is mentioned about Jesus.