MongoDB shell version: 2.2.0-rc1-pre-
> help misc
        b = new BinData(subtype,base64str)  create a BSON BinData value
        b.subtype()                         the BinData subtype (0..255)
        b.length()                          length of the BinData data in bytes
        b.hex()                             the data as a hex encoded string
        b.base64()                          the data as a base 64 encoded string
        b.toString()

        b = HexData(subtype,hexstr)         create a BSON BinData value from a hex string
        b = UUID(hexstr)                    create a BSON BinData value of UUID subtype
        b = MD5(hexstr)                     create a BSON BinData value of MD5 subtype
        "hexstr"                            string, sequence of hex characters (no 0x prefix)

        o = new ObjectId()                  create a new ObjectId
        o.getTimestamp()                    return timestamp derived from first 32 bits of the OID
        o.isObjectId()
        o.toString()
        o.equals(otherid)

        d = ISODate()                       like Date() but behaves more intuitively when used
        d = ISODate('YYYY-MM-DD hh:mm:ss')    without an explicit "new " prefix on construction
> o = new ObjectId()
ObjectId("5014000dd3f4f73f93ee6fb6")
> o.isObjectId()
Sat Jul 28 11:07:07 TypeError: o.isObjectId is not a function (shell):1
> o.isObjectId
true
>