<s>
Virtual	B-General_Concept
graffiti	I-General_Concept
consists	O
of	O
virtual	O
or	O
digital	O
media	O
applied	O
to	O
public	O
locations	O
,	O
landmarks	O
or	O
surfaces	O
.	O
</s>
<s>
Virtual	B-General_Concept
graffiti	I-General_Concept
applications	O
utilize	O
augmented	B-General_Concept
reality	I-General_Concept
and	O
ubiquitous	B-Architecture
computing	I-Architecture
to	O
anchor	O
virtual	B-General_Concept
graffiti	I-General_Concept
to	O
physical	O
landmarks	O
or	O
objects	O
in	O
the	O
real	O
world	O
.	O
</s>
<s>
Virtual	B-General_Concept
graffiti	I-General_Concept
is	O
aimed	O
at	O
delivering	O
messaging	O
and	O
social	O
multimedia	O
content	O
to	O
mobile	O
applications	O
and	O
devices	O
based	O
on	O
the	O
identity	O
,	O
location	O
,	O
and	O
community	O
of	O
the	O
user	O
.	O
</s>
<s>
This	O
overall	O
effort	O
focuses	O
on	O
creating	O
new	O
mobile	O
experiences	O
based	O
on	O
merging	O
virtual	B-Application
reality	I-Application
,	O
telepresence	B-Application
,	O
and	O
global	O
positioning	O
systems	O
.	O
</s>
<s>
This	O
involves	O
anchoring	O
a	O
virtual	B-Application
reality	I-Application
experience	O
at	O
a	O
physical	O
location	O
.	O
</s>
<s>
The	O
phrase	O
"	O
virtual	B-General_Concept
graffiti	I-General_Concept
"	O
has	O
existed	O
for	O
a	O
long	O
time	O
and	O
has	O
been	O
applied	O
to	O
various	O
applications	O
over	O
the	O
years	O
.	O
</s>
<s>
During	O
a	O
research	O
fellowship	O
at	O
the	O
University	O
of	O
Georgia	O
in	O
2003	O
,	O
Kit	O
Hughes	O
developed	O
a	O
system	O
in	O
which	O
users	O
with	O
WiFi-enabled	O
mobile	O
devices	O
could	O
mark	O
up	O
buildings	O
in	O
downtown	O
Athens	O
,	O
Georgia	O
,	O
with	O
their	O
own	O
virtual	B-General_Concept
graffiti	I-General_Concept
via	O
a	O
process	O
known	O
as	O
tagging	O
.	O
</s>
<s>
In	O
a	O
project	O
from	O
Lancaster	O
University	O
,	O
mobile	O
phones	O
are	O
used	O
as	O
digital	O
mediums	O
,	O
using	O
RFID	B-Application
tags	I-Application
to	O
identify	O
markable	O
objects	O
.	O
</s>
<s>
The	O
RFID	B-Application
tags	I-Application
can	O
hold	O
the	O
identities	O
of	O
the	O
last	O
five	O
people	O
to	O
leave	O
graffiti	O
.	O
</s>
<s>
When	O
another	O
user	O
comes	O
within	O
range	O
of	O
an	O
RFID-tagged	O
object	O
,	O
the	O
associated	O
graffiti	O
is	O
downloaded	O
onto	O
their	O
mobile	O
device	O
.	O
</s>
