I've researched into several scent interactive projects and found out how actually their projects are working and the objective of creating such projects. I've spent an hour researching on smell senses and topic-related projects.

SMELL SENSES
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http://www.youtube.com/watch?v=bJWiU0qsPfA  (interactive sound and smell installation)
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- it's an installation where audiences are able to smell things like candy, fall and fish which based on the interviews Gwenn-Ael Lynn was conducted with long term chicago residents.
- user's movement is tracked by hidden c-mos camera, which will trigger the smell difuser and also soundtrack.
- it's a simulation of Chicago for the users using of sound and smells.

|| found that the user in the video is rejecting the smell of "FALL"
|| it was unbearable for the user.
|| not every smell is acceptable by everyone. for example: petrol smell, smell of matches burning, etc...
|| interesting project to introduce Chicago through smell and sound instead of visual which is quite rare.


http://www.displaycult.com/exhibitions/odor_limits.html
ODOUR LIMITS
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- an installation that explores potential of smell in aesthetic experience. There are several installation which include: Smellscape, scents, trashcans,  and smell it.
Smell scape:
-created a unique arrangement of scents from a series of 'notes' found along the route of Philleas Fogg's circumnavigation of the globe, ranging from the pleasant to the unsavoury.
-The degree to which the various 'notes' are perceptible will vary according to each visitor's sense of smell and previous personal experience.

scents, trash cans
- users required to lift the cover of trash cans to inhale the smell and guess the distinctive odors of the residents in an apartment complex in northwest london.

Smell It: A Do-It-Yourself Smell Map, 2008.
- an interactive wall where visitors will be given a street map and then invited to walk around the neighborhood to record their olfactory experiences.
-viewers can add their odorous encounters to a wall-sized, collectively - drawn map to show the diversity of subjective responses to smell and shifting of the neighborhood's smellscpe from one day to the next.
- using smell experience to create a cartography.

|| shows that different smell brings different memory/relationship to a human, and different people have different memory towards the smell.
|| it's an interesting to see how the users visualise what they smell and what are their experiences.
|| it's also interesting to see how smells trigger one's emotion and memory as smell is the only sense that cannot be turned off.

http://www.freeturbine.com/index.php/news/artists-news/item/peter-de-cupere-olfactory-art
A mini exhibition by Peter De Cupere
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- exhibition that showcases smell sense installations
- audiences are able to experience the smell of certain artwork in the exhibition such as smell of cigaratte, toothpaste, peppermint smell, strawberries, mushrooms, grass and more.
- different artwork emits different kind of smell.
- there is also a "smell me project" where people's necks are stamped with the words "smell me" and everyone goes around sniffing each other exploring others' scents and to see which attract and repel.
- besides, an installation called "olfactiano" is a piano-like instrument that emits different smells when played, which is called the 'scent concerts'

|| this exhibition shows that smell is another sense that helps human to know things better
|| sense of smell can also be transformed into art , interactive
|| smell sense project are rare compared with visual interactive projects. it gives a whole new experience to the users instead of using, sight or hear senses.
|| provide different experience to against stereotype towards certain thing. for example: trash can not necessary smells bad when you see it. it may have different kind of smell.
|| smell also helps in imagination


http://www.behance.net/KnutUlmer/frame/1261945
http://en.wikibooks.org/wiki/Advanced_Interactive_Media/The_Future_For_Immersive_Media


Besides, I have also found that there is a new digital scent technology which is able to bring smell from the computer to the users.

New technology: Smell senses
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http://sdmcse2006.pbworks.com/f/print1.pdf
-scentware (hardware and software) which will produce smell.
-iSmell digital scent technology is created by DigiScents which will enable scents to be broadcast from the Web.
-iSmell is about the size of a PC speaker that connects to a PC via a USB port. iSmell will emit smells from a "palette" of 128 chemicals stored in a cartrigde.
- it can be used in Marketing, entertainment, education and also medical especially perfume manufactures where they can send the sample of the perfume via email to the users/consumers.
- it also can be used in interactive game to enhance the user experience while playing through creating more realistic ambiance besides using sound and images. 
- "this digital smell will revolutionised the world, ANd at every place we will require this device, such as for scented mail, movies, songs..."
- "it will become our need in future"

Since digital smell is not popular yet and even most of the people are not aware about it. If this kind of technology is being popularised, I believe that users are able to fully maximise their experience while interacting with certain devices.