The Speech Accent Archive
Each individual sample page contains a sound control bar, a set of the answers to 7 demographic questions, a phonetic transcription of the sample,1 a set of the speaker's phonological generalizations, a link to a map showing the speaker's place of birth, and a link to the Ethnologue language database.
The archive also contains a set of native language phonetic inventories so that you can perform some contrastive analyses.