According to "Yoga and Yogic Powers" by the old Indian yogi Swami Gupta (a book I've discussed before, here), the answer to your question is yes:

Masters do incarnate on this earth by mere will to initiate the people of the world into the mysteries of Truth, and splendors of eternal beauty and Divine Truth. Masters, when incarnate on this earth, live as an ordinary person and can hardly be distinguished from an average person in life, except through their deeds. By his wish, a Master, while living on this earth, can make anyone here recognize him, that he is one of the Great Masters who have incarnated on this earth. Without their blessings and wish, no one can know that the Masters have incarnated on this earth, as they walk the street with the mortal people only to help them and raise their moral and spiritual standards of life, which will bring rareification and purification of their mental and astral body and prepare them for their luminous journey in the astral.

Masters also from beyond this world, watch and help the awakening of new lives upon the surfaces of numerous worlds, growth of human life that inhabit those worlds, and through their vast power of perception they note that on each solar system, life, motion and activity are kept in harmony with the order of the Universe...

The Great Masters are able to control and direct creation, preservation and dissolution by the mighty influences of their will power. Their will power is released merely by their wish. It is purely a mental action. Just as you will to take another step while you walk on the street, similarly, the Great Masters will to do a thing and the thing happens.

Masters can materialize on the earth simply by their wish. They can appear before you in a second and disappear in the next second. It is these masters who control the destiny of the world. At present their live on this earth seven Great Masters. One of them is in the United States of America. They work in close harmony with each other. One can know them and recognize them only by their Grace.

Regarding your question, "I personally extend this not only to our planet, but every planet and stars as well. Do you believe their consciousness can/do operate on a level as [relatively] 'low' as ours?"

Bashar mentioned something that sounded a bit similar during a seminar. A girl in the audience asked a question about beings she had been visiting in dreams or astral travel, which she referred to as "The Turquoise People." Not missing a beat, Bashar immediately responded that these were highly evolved beings that spent most of their existence creating planets, constructing worlds throughout the Universe. They sounded a bit like Earth elementals, operating on a much higher frequency than human beings. Their true name was unpronounceable, but Bashar said the closest thing to it that we could conceive of was the sound of an earthquake.

EDIT 5/10/2013

In response to the comment below "Where do the rest of the masters stay, in which countries?"

Gupta's book (quoted above) only mentions one of these masters who lives in the United States. On the same page, he also mentions that "Gorakhnath, Sadasiva, etc., are some of the highly evolved souls who lived on this earth." But it's not clear if he is saying that these are two of the "Seven Great Masters" described above.

So that would seem to be the end of it. However...

After reading Dipen's question, something caused me to pick up another book off my shelf...a mysterious force seemed to be pulling me...towards the book "Great Masters of the Himalayas", previously referred to here.

After perusing it some more, I think that this book is referring to the same "Great Masters."

The author, Rishi Singh Gherwal, recounts how after many years of feeling a "strong desire" to meet with a great legendary master, he had a dream in which such a being instructed him to go to Brindavan, five miles west of the city of Mathura, in Northern India. The author traveled there, and was approached in the flesh by this same "Great Master." His name was Bhagavan Puriji, and he could teleport, bi-locate, levitate, shape-shift, frolic with wild tigers, materialize things out of thin air, and express many other powers at will. When Gherwal expressed astonishment at these feats, calling them "miracles", Puriji merely laughed and said they were "easy" and no big deal to do, once you knew how to do them.

Puriji led Gherwal on a journey from town to town, deep into the Himalayas, and into Tibet. Puriji would teleport from destination to destination, while Gherwal had to make the arduous journey on foot, hiking from town to town, where he would rendezvous with Puriji.

These are the towns they visited, meeting with other "master" yogis who were able to perform similar feats and powers:

INDIA:

Hardwar

The Cave of Nasik

The Cave of Bagh - 45 miles east of Mandhu -- a meeting here with other Great Masters

Hastinapur

Badrinath

Kandarnath

NEPAL:

Muktinath

TIBET:

Manasarovar Lake

Lhatse

Shigatse

BHUTAN:

The Temple Poratat Sanga (now Taktsang) - a meeting with more Great Masters here

And that's about all the info I have right now. As to where they are right now, who can say? :)

Well, if there is, they would look sorta funny if they were wearing wings or something of the like... so, I would imagine they would probably absorb human form to fit in.

@Dragonflybreeze "absorb human form to fit in" i like it ... greater entities living in parallel universes, human form living here on earth, sequential regular existence ... all this reminds me of this enlightening video of how the two brains, serial and parallel brains function ... and further into the video there is even suggestion of hybrid reptilian forms, that is, the form of the energy body that envelopes the human form

http://www.youtube.com/watch?v=UyyjU8fzEYU