Are there Christian denominations that promote making themselves eunuchs? In the same way that certain denominations promote (and in some cases, require) their adherents to remain celibate and/or non-married, are there any that promote making themselves eunuchs for the sake of the kingdom of God like Jesus talked about in Matthew 19?

Jesus brought up the practice as if it was somewhat common.


  Matthew 19:9-12 ESV And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.” The disciples said to him, “If such is the case of a man with his wife, it is better not to marry.” But he said to them, “Not everyone can receive this saying, but only those to whom it is given. For there are eunuchs who have been so from birth, and there are eunuchs who have been made eunuchs by men, and there are eunuchs who have made themselves eunuchs for the sake of the kingdom of heaven. Let the one who is able to receive this receive it.”


I've heard of individual men that have done this, but never a group.
While not a denomination, the Church Father / Heretic Origen is probably your most famous practitioner.  Then again, even the other Church Fathers had a difficult time with his understanding of Scripture on several accounts.

There are few denominations that would encourage the practice, as it tends to reduce the number of followers dramatically.  Historically, any group that discourages procreation - such as the Shakers - found it difficult to survive more than a generation.  While they may not have castrated themselves, their celibacy functionally made them eunuchs.  

Jesus was not necessarily implying normative behavior here - indeed, a better reading would say, "there are a few who went this way."  Priestly celibacy is really the natural outcome - but notice it is considered a ascetism for the few.  Not all can handle it.