One of the main challenges for privacy-aware location-based systems is to strike a balance between privacy preferences set by users and location accuracy needed by Location-Based Services (LBSs). To this end, two key requirements must be satisfied: the availability of techniques providing for different degrees of user location privacy and the possibility of quantifying such privacy degrees. To address the first requirement, we describe two obfuscation techniques. For the second requirement, we introduce the notion of relevance as the estimator for the degree of location obfuscation. This way, location obfuscation can be adjusted to comply with both user preferences and LBS accuracy requirements.