The following sites are advertising for art interns. Some lean more towards graphic design, but say illustration skills are a plus, some are more illustrative. Some of these are paid internships, others are not. Take note of the deadlines for application, some are sooner than others.
http://www.blueskystudios.com/content/company-internshipsdetail.php?id=88
http://www.utne.com/about/internships.aspx
http://www.entertainmentcareers.net/id/?id=103272
http://adidas.jobpartners.com/jpapps/adidas_us/jobs/jobview.jsp?0.41186709242509&requestno=RQ00013477&brandBars=FP00000048
http://www.internjobs.com/do/details/9669
http://newton.newtonsoftware.com/career/JobIntroduction.action?id=4028f88b26c50f6c0126e23d3edc0dc6&source=Simply+Hired
https://mh.taleo.net/careersection/3/jobdetail.ftl?lang=en&job=356390&src=JB-11820
http://www.retailgigs.com/job.asp?id=22670394&aff=5B69D171-E6DF-4407-9864-3092BB91A6F2 http://www.idealist.org/if/i/en/av/Internship/143310-258
http://lag.catsone.com/careers/index.php?m=portal&a=details&jobOrderID=155984
http://www.metmuseum.org/education/er_internship.asp http://www.rsinternships.com/applications/posting.php3?ID=29 http://www.rsinternships.com/
http://www.chabotspace.org/getinvolved/internship/graphicdesign_internship.asp
http://www.internweb.com/ http://www.turner.com/careers/internships_domestic.html
http://www.columbusinternships.com/search/detail/882
http://www.hallmark.com/webapp/wcs/stores/servlet/article|10001|10051|/HallmarkSite/AboutHallmark/HallmarkCareers/CAREERS_TROVIX_LANDING_PAGE
http://www.hallmark.com/webapp/wcs/stores/servlet/article|10001|10051|/HallmarkSite/AboutHallmark/HallmarkCareers/CAREERS_TROVIX_LANDING_PAGE
